New comprehensive biochemistry vol 31 biochemistry of lipids, lipoproteins and membranes 3rd edition

BIOCHEMISTRY OF LIPIDS,
LIPOPROTEINS AND MEMBRANES


New Comprehensive Biochemistry

Volume 31

General Editor

G. BERNARD1
Paris

Amsterdam - Lausanne

-

ELSEVIER
NewYork - Oxford

-

Shannon - Tokyo


Biochemistry of Lipids,
Lipoproteins and Membranes

Editors

DENNIS E. VANCE and JEAN E. VANCE
Lipid and Lipoprotein Research Group, Faculty of Medicine,
328 Heritage Medical Research Centre, Edmonton, Alberta, Canada T6G 2S2

1996
Amsterdam

-

Lausanne

-

ELSEVIER
NewYork - Oxford

-

Shannon

-

Tokyo


Elsevier Science B.V.
Sara Burgerhartstraat 25
P.O. Box 21 1, 1000 AE Amsterdam, The Netherlands

L i b r a r y of Congress C a t a l o g i n g - i n - P u b l i c a t i o n

Data

B i o c h e m i s t r y o f l i p i d s , l i p o p r o t e i n s , and membranes / e d i t o r s , Dennis
E. Vance and J e a n E. Vance.
cm. -- (New c o m p r e h e n s l v e b i o c h e m i s t r y
v . 31)
p.
I n c l u d e s b i b l i o g r a p h i c a l r e f e r e n c e s and i n d e x .
a l k . p a p e r ) . -- ISBN 0-444-82364-6
I S B N 0-444-82359-X ( h b k .
(pbk.
a l k . paper)
1. Lipids--Metabolism.
2. L i p o p r o t e ~ n s - - M e t a b o l i s m . 3. Membrane
lipids--Metabolism.
I. V a n c e . Dennis E. 11. Vance, J e a n E.
111. S e r i e s .
OD415.N48 v o l . 31

.

OP75 I 1
574.19'2 s--dc20
[574.19'2471

96-22129

CIP

The cover illustration, which originally uppeured in the Journul
is reproduced with the kind permission of Dr E.A. Dennis.

ofBiological Chemistrv,

ISBN 0 444 82359 X (hardbound)
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Printed in The Netherlands


V

Preface
This is the third edition of this advanced textbook which has been written with two major

objectives in mind. One is to provide an advanced textbook covering the major areas in
the fields of lipid, lipoprotein and membrane biochemistry and molecular biology. The
chapters within this volume are written for students who have already taken an introductory course in biochemistry, who are familiar with basic concepts and principles of biochemistry and have a general background knowledge in the area of lipid metabolism.
This book should therefore provide the basis for an advanced course for students in the
biochemistry of lipids, lipoproteins and membranes.
The second objective of this book is to provide a clear summary of these research
areas for scientists presently working in, or about to enter, these and related fields. This
book should satisfy the need for a general reference and review book for scientists
studying lipids, lipoproteins and membranes. Excellent up-to-date reviews are available
on the various topics covered by this book, and many of these reviews are cited in the
individual chapters. However, this book remains unique in that it is not a series of exhaustive reviews of the various topics, but rather is a current, readable and critical summary of these areas of research. This book should allow scientists to become familiar
with recent developments related to their own research interests, and should also help
clinical researchers and medical students keep abreast of developments in basic science
that are important for subsequent clinical advances.
All the chapters have been extensively revised since the last edition and up-to-date information is included. Three new chapters have been included to take into account substantial new insights into the roles of glycerolipids in signal transduction, lipid metabolism in adipose tissue, and lipid metabolism in plants. We have not attempted to cover in
detail the structure and function of biological membranes since that subject is covered
already in a number of excellent books. However, the first chapter does contain a summary of the principles of membrane structure as a basis for the subsequent chapters.
We have limited the number of references cited and emphasized review articles. However, some readers may wish access to the primary literature in some instances. Thus, we
have introduced a novel approach to literature citation suggested by Charles Sweeley. In
some of the chapters reference has been made to published work by citing the name of
the senior author and the year in which the work was published. This should allow the
reader to find the original citation via a computer search.
The editors and contributors assume full responsibility for the content of the various
chapters and we would be pleased to receive comments and suggestions for future editions of this book.
We are indebted to many other people who have made this book possible. In particular we extend our thanks to Brad Hillgartner, Deborah Hodge, Laura Petrosky, Ten-ching
Lee and Shirley Poston.
Dennis and Jean Vance
Edmonton, Alberta, Canada
March 1996

This Page Intentionally Left Blank


VII

List of contributors
D.A. Bernlohr, 257
Department of Biochemistry, University of Minnesota, S140 Gortner Lab, 1479 Gortner
Avenue, St. Paul, MN 55108-1022, USA
H.W. Cook, 129
Atlantic Research Centre, Dalhousie University, Halifm, Nova Scotia, Canada, B3H
4H7
J.E. Cronan Jr., 35
Departments of Microbiology and Biochemistry, University of Illinois, Urbana, IL
61801, USA
P.R. Cullis, I
Department of Biochemistry and Molecular Biology, Faculty of Medicine, University of
British Columbia, Vancouver, B. C., Canada, V6T 123
R.A. Davis, 341,473
Department of Biology, San Diego State University, San Diego, CA 92182-0057, USA
P.A. Edwards, 341
Department of Biological Chemistry, UCLA School of Medicine, 33-257 CHS, P.O. Box
951 737, LQS Angeles, CA 90095-1737, USA
D.B. Fenske, 1
Department of Biochemistry and Molecular Biology, Faculty of Medicine, University of
British Columbia, Vancouver, B. C., Canada, V6T 123
P.E. Fielding, 495
Cardiovascular Research lnstitute, University of California Medical Center, San Francisco, CA 94143-0130, USA
C.J. Fielding, 495

Cardiovascular Research Institute, University of California Medical Center, San Francisco, CA 94143-0130, USA
F.A. Fitzpatrick, 283
Cell Biology and Inflammation Research, Upjohn Company, 301 Henrietta Street, Kalamazoo, MI 49001, USA
A.G. Goodridge, 101
Department of Biochemistry, University of Iowa, Iowa City, IA 52242, USA
M.J. Hope, 1
Division of Dermatology, Faculty of Medicine, University of British Columbia, Vancouver, B.C., Canada, V5Z l L 7
S. Jackowski, 35
Department of Biochemistry, St. Jude Children’s Research Hospital, Memphis, TN
38101, USA
J.D. Lambeth, 237
1510 Clifton Road NE, Rollins Research Center #4001, Department of Biochemistry,
Emory University Medical School, Atlanta, GA 30322, USA
A.H. Merrill, Jr., 309
Department of Biochemistry, 41 13 Rollins Research Center, Emory University, Atlanta,
GA 30322-3050. USA


VIII
J.B. Ohlrogge, 363
Department of Botany and Plant Pathology, Michigan State University, East Lansing, MI
48824-1312, USA
R.A.F. Reithmeier, 425
MRC Group in Membrane Biology, Department of Medicine, Room 7344, Medical Sciences Building, University of Toronto, Toronto, Ontario, Canada, M5S IA8
C.O. Rock, 35
Department of Biochemistry, St. Jude Children’s Research Hospital, Memphis, TN
38101, USA
S.H. Ryu, 237
Signal Transduction Laboratory, Department of Life Sciences, Pohang University of Science and Technology, Pohang, 790-600, South Korea
L.M. Salati, 101

Department of Biochemistry, West Virginia University, Morgantown, WV 26506, USA
K.M. Schmid, 363
Department of Biological Sciences, Butler University, 460 Sunset Avenue, Indianapolis,
IN 46208-3485, USA
W.J. Schneider, 517
Department of Molecular Genetics, University and Biocenter Vienna, Dr. Bohr - Game
912, A-1030 Vienna, Austria
H. Schulz, 75
City College of CUNY, Department of Chemistry, New York, NY 10031, USA
M.A. Simpson, 257
Department of Biochemistry, University of Minnesota, S140 Gortner Lab, 1479 Gortner
Avenue, St. Paul, MN 55108-1022, USA
W.L. Smith, 283
Department of Biochemistry, Michigan State University, East Lansing, MI 48824, USA
F. Snyder, 183
Medical Sciences Division, Oak Ridge Associated Universities, Post Ofice Box I 17, Oak
Ridge, TN 37831-0117, USA
C.C. Sweeley, 309
Department of Biochemistry, Michigan State University, East Lansing, MI 48824, USA
J.E. Vance, 473
Lipid and Lipoprotein Research Group, University of Alberta, Edmonton, Alberta, Canada, T6G 2S2
D.E. Vance, 153
Lipid and Lipoprotein Research Group and Department of Biochemistry, University of
Alberta Edmonton, Alberta, Canada, T6G 2S2
D.R. Voelker, 391
Department of Medicine, The National Jewish Center for Immunology and Respiratory
Medicine, 1400 Jackson Street, Denver, CO 80206, USA
M. Waite, 21 1
Department of Biochemistry, Bowman Gray School of Medicine, Wake Forest University,
Winston-Salem, NC 27157, USA

IX

Contents
Preface.......................................................................................................................................

V

List of contributors ....................................................................................................................

VII

Chapter 1. Physical properties and functional roles of lipids in membranes
P .R . Cullis. D .B . Fenske and M .J . Hope....................................................................................

1.
2.

1

Introduction and overview ........
Lipid diversity and distribution
2.1. Chemical diversity of lipids ............
...................................
2.2. Membrane lipid composi
2.3. Transbilayer lipid asymmetry ..........
3. Model membrane systems .................................................................................................
3.1. Lipid isolation and purifi
.................

3.2. Techniques for making model membrane vesicles ..................................................
3.3. Techniques for making planar bilayers and monolayers .........................................
3.4. Reconstitution of integral membrane proteins into vesicles ....................................
4. Physical properties of lipids ...............................................................................................
4.1. Gel-liquid-crystalline phase behavior
.....
4.2. Lipid polymorphism ................................................................................................
4.3. Factors which modulate lipid polymorphism
4.4. The physical basis of lipid polymorphism ..............................................................
5. Lipids and the permeability properties of membranes .......................................................
5.1. Theoretical considerations.......................................................................................
5.2. Permeability of water and non-electrolytes .............................................................
5.3. Permeability of ions ..................................................................
.....................
........
..............................
6. Lipid-protein interactions .............
6.1. Extrinsic proteins ....................................................................................................
6.2. Intrinsic proteins ...........................................
..................................................................
7. Lipids and membrane fusion
7.1. Fusion of model systems .........................................
7.2. Fusion of biological membranes .............................................................................
.....................
8. Model membranes and drug delivery ............................
..........................................................................................
9. Future directions ...........
References .................................................................................................................................

3

3
4
6
8
8
9
9
11
13
13
17
20
21
22
22
23
24
25
25
26
27
27
28
30
32
32

Chapter 2. Lipid metabolism in prokaiyotes
C.O. Rock. S . Jackowski and J.E. Cronan Jr.............................................................................

35

1.
2.

3.

4.

5.
6.

The study of bacterial lipid metabolism ....
...........................................................
Historical introduction ..............................................................................................
An overview of lipid metabolism in E . coli ...............
Genetic analysis of lipid metabolism .................................................................................
Membrane systems of E . coli ...............................
....................................
Lipid biosynthetic pathways in E . coli .....

1

35
35
36
36
40
41

X
6.1.
6.2.
6.3.
6.4.

Acyl carrier protein (ACP)
Acetyl-CoA carboxylase ...........,..........................................

.....,.................................
'

..................................
.............................................................
e ................. ............

......

6.4.3. 3-Hydroxyacyl
6.4.4. Enoyl-ACP reductase
................................. ....
Product diversification ..................................... .......... ..........
....................................................................
Transfer to the membrane
~

7.

6.5.

6.6.
6.7.
6.8.
Lipopolysaccharide biosynthesis ...................

8.2.
9.

55

..............................................

Thioesterases ......

.....................

Phospholipid turnover ...................................
9.1. The diacylglycerol cycle

...................,...............

10. Inhibitors of lipid metabolism

11.3. Transcriptional regulation of the genes of fatty acid synthesis. ..............................
11.4. Regulation of phospholipid headgroup composition ............
11.5. Coupling of fatty acid synthesis to phospholipid synthesis ....................................
11.6. Coordination of phospholipid and macromolecular synthesis ................................
12. Lipid metabolism in bacteria other than E. Cali ..............................
..........,.......................
12.1. Bacteria lacking unsaturated fatty acids .........

12.2. Bacteria containing phosphatidylcholine ..............................................
12.3. Bacteria synthesizing unsaturated fatty acids by an aerobic pathway .....................
12.4. Bacteria with a multifunctional fatty acid s
12.5. Bacteria with intracytoplasmic membranes
..................................
12.6. Other bacterial oddities .........................................................................
...................................
12.7. Lipids of non-bacterial (but related) organisns
13. Future directions .......................................................................................... ....

....................

' . I . . . . . . . . . . . . . . . .

...................................................................................

Chapter 3. Oxidation of fatty acids
H . Schulz ..........................................................

1.
2.
3.

~

.........................................................................

The pathway of /%oxidation: a historical account ..............................................................
Uptake and activation of fatty acids in animal
Fatty acid oxidation in mitochondria ........... ....................................................................

3.1. Mitochondria1 uptake of fatty acids ........
.............* .................
3.2. Enzymes ofa-oxidation in mitochondr
3.3. P-Oxidation of unsaturated and odd-ch
I ,

41
42
43
44
45
46
47
47
47
49
50
54

55
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58
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62

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73

75
75
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78
78
80
84


XI
3.4. Regulation of fatty acid oxidation in mitochondria ...........................................
3.5. Inhibitors of mitochondrial fatty acid oxidation .....................................................
4. /?-Oxidation in peroxisomes ............................
5. Fatty acid oxidation in E . coli
.........................................................................

6. Inherited diseases of fatty acid oxidation .........
7. Future directions ................................................................................................................
References ..............................................................

87
89
91
93
96
97
98

Chapter 4 . Fatty acid synthesis in eukaryotes
L.M. Salati and A.G. Goodridge ................................................................................................

101

1.
2.
3.
4.

Introduction .......................................................................................................................
Signals in blood that mediate the effects of diet on fatty acid synthesis
Which enzymes regulate fatty acid synthesis? ...................................................................
..............................
Regulation of substrate supply ....
4.1. Production of pyru
4.2. Production of citra
4.3. Production of NADPH ....

.....................................
Regulation of the catalytic effici
5.1. A key regulatory reaction .....................
..........................................
5.2. Structure and reaction mechanism ..........................................................................
5.3. Regulation by citrate
5.4. Regulation by long-c

8. Future directions ...............................................................................
Acknowledgements ...................................................................................................................
References .................................................................................................................................

101
102
103
104
104
105
105
105
105
106
107
108
109
113
115
116
116
117

117
119
120
122
122
124
125
126
126

Chapter 5. Fatty acid desaturation and chain elongation in eukaryotes
H .W. Cook .................................................................................................................................

129

5.

........................................
6.

Fatty acid synthase........................................................................................
6.1. Animal fatty acid synthase: the component reactions

6.3.
7.

Regulation of enzyme concentration ..............................................
7.1. Regulation of the expression of the lipogenic enzymes ..........................................

7.3.

1.
2.
3.

Animal fatty acid synthase: structural organization .....

Regulation in cells in culture
7.3.1. Pre-adipocyte cell lines ....................................................

Introduction .................................
.....................................
Historical background ..........................................................................
Chain elongation of long chain fatty acids
.........................................
3.1. The endoplasmic reticulum elongation system ..................................
3.2. The mitochondrial elongation system
..........................................
3.3. Functions of elongation systems .......................................................

129
131
131
133
134
135


Formation of monounsaturated fatty acids by oxidative desaturation ...............................
.................

4.1. Nomenclature to describe double bonds
4.2. Characteristics of monoene-formingdes
es ................ ....................
4.3. Modification of A9 desaturase activities in vitro ............
4.4. Age-related, dietary and hormonal regulation of A9 desaturase ........... ..................
5. Formation of polyunsaturated fatty acids ............
5.1. Characteristics in animal systems............................................................................
5.2. Essential fatty acids: a contribution of plant systems
5.3. Families of fatty acids and their metabolism...........................................................
5.3.1. The (n-6) family
5.3.2. The (n-3) family .........................................................................................
5.3.3. The (n-9) family ................
5.3.4. The (n-7) family .......
.....................................................................
ions of polyunsaturated acid synthesis...
5.4. Age-related, dietary and ho
6. Unsaturated fatty acids with trans
7. Abnormal patterns of distr
rated fatty acids ......_..........
7.1. Essential fatty acid deficiency.................................................................................
7.2. Zinc deficiency......
7.3. Relationships to plasma c
........................................................................
7.4. Other clinical disorders
8. Future
.....
References
.....

4.

Chapter 6. Glycerolipid biosynthesis in eukaryotes
D.E. Vance.................................................................................................................................

2.

3.

4.

.....,...........................................................................................................
Phosphatidic acid bios
2.1. Glycerol-3-P acyltransferase
2.2. 1-Acylglycerol2.3. Dihydroxyaceto
2.4. Phosphatidic acid phosphohydrolase ................... ............. ............. ........... ..............
Phosphatidylcholine biosynthesis
3.1. Historical background .............................................................................................
3.2. Choline transport and oxidation.
..........................
3.3. Choline kinase ...
3.4. CTP:phosphoch
3.5. CDP-choline:1,2-diacylglycerolcholinephosphotransferase ..................................
3.6. Phosphatidylethanolamine N-methyltransferase .....................................................
Regulation of phosphatidylcholinebiosynthesis ...............................................................
4.1. The rate-limiting reaction
4.2. The translocation
4.3. Regulation of phos
s ......................................
4.4. Phosphorylation of cytidylyltransferase............................ ...... ................................
4.5. Expression of cytidylyltransferase is also regulated................................................

4.6. Interrelationships among phosphatidylethanolamine methylation, the CDPcholine pathway, hepatoma cell division and liver tumor suppression.

135
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137
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149
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164
164
165


5.

6.
7.

8.

9.

10.
11.
12.

13.

Phosphatidylethanolamine biosynthesis ..................
....
5.1 . Historical background and biosynthetic pathways ...................................................
5.2. Enzymes of the CDP-ethanolamine pathway
5.3. Regulation of the CDP-ethanolamine pathway .......................................................
5.4. Phosphatidylserine decarboxylase
...................
Triacylglycerol biosynthesis ..............._..
.................................................... ....._.......... ........
Phosphatidylserine biosynthesis ..........
7.1. Historical developments and bi
..................
7.2. Chinese hamster ovary cell mutants and regulation ...
Inositol phospholipids ........................................................................................................
8.1. Historical developments ......
...................
8.2. Biosynthetic enzymes..............................................................................................
Polyglycerophospholipids ...
..................,..,..............
.......................
9. I . Historical developm
9.2. Enzymes and subcel
n ..........................................................,................
Remodeling of the acyl substituents of phospholipids ......................................................
Regulation of gene expression in yeast ............................................
...................
Glycosyl phosphatidylinositols for attachment of cell surface proteins ............................
...................

Future directions .................................................................
......................................................

Chapter 7, Ether-linked lipids and their bioactive species: occurrence, chemistry,
metabolism, regulation, and function
F. Snyder ...................................................................................................................................

1.
2.

Introduction ........................................ ....................................
Synopsis of historical developments.....

5.
6.

Natural occurrence ...........................................................................
Biologically-active ether lipids
.....................................................
6.2.

Receptors and antagonists

.....................................

166
166
i66
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168

169
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171
171
172
172
174
175
176
177
179
180

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184
185
187
187
189
189
190
191
191
191
192
192

192
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195
195
195
196
198

198
7.3.3.

PAF transacetylase ......................................................

200
200


XIV
.....................................................................
Catabolic enzymes ............................
8. I . Ether lipid precursors ..............................................................................................
........................,...,...................,...................
8.1.1. Fatty alcohols .........

202
202
202
202
202
................................... 202

203
8.2.3. Phospholipases and lipases ........................................
.................... 203
204
8.3. PAF and related bioactive species ...........................................................................
205
9. Metabolic regulation .......................................................................
.................................... 207
207
.................................... 207
208
11. Future directions
209
Acknowledgements ........................................................
.....,............,......................................................................... 209
References ............

8.

Chapter 8. Phospholipases

M. Waite ....................................................................................................................................

21 1

Overview ................................................................................................................
1.l. Definition of phospholipases ...........................................
................,...................................................
1.2. Assay of phospholipases ...........
1.3. Interaction of phospholipases with interfaces ........

1.3.1. Increased effective substrate concentration. ...............................................
1.3.2. Orientation of the phospholipid molecule at the interface .........................
1.3.3. Enhanced diffusion of the products from the enzyme ................................
1.3.4. Conformational change
1.3.5. Nature of the aggregated lipid
2. The phospholipases ........................................
2.1. Phospholipase A, ......................
.....................................................................
2.1.1. Escherichia coli phosph
2.1.2. Lysosomal phospholipase A, .....................................................................
2.1.3. Lipases with phospholipase A1 activity ......................................................
2.2. Phospholipase B and lysophospholipases ................................
2.2.1. Penicillium notatum phospholipase B ........................................................
................
.................
2.2.2. Mammalian lysophospholipases A,
2.3. Phospholipase A2 .......... .................................................... ......................................
2.3.1. Groups 1-111 phospholipases A2.
..............................................
2.3.2. Group IV (cytosolic) phospholipases A, ...................................................
2.3.3. Ca2+-independent and other phospholipases A2 ...
2.4. Phospholipase C .................................................................
2.4.1. Bacterial phospholipases C ...................................
2.4.2. Mammalian phospholipases C ..............................
2.5. Phospholipase D ..................................................................
3. Future directions .....................................
..................................
References ............................................................................................

21 1

21 1
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217
217
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22 I
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235

1.

Chapter 9. Glycerolipids in signal transduction
J.D. Lambeth and S.H.Ryu ........................................................................................................

237

Introduction: glycerolipids as a source of bioactive molecules .........................................
Phosphatidylinositol cycle ........
2.1. The discovery of the pho
................................................
2.2. Inositol phosphate metab
f intracellular calcium levels ........
2.3. Phosphatidylinositol-phospholipaseC isoforms: occurrence and regulation ..........
3. Diacylglycerols ..................................................................................................................
3.1. Protein kinase C and its regulation by diacylglycerol ........................................
3.2. Evidence for novel mechanisms of diradylglycerol generation ...........
4. Phosphatidylcholine hydrolysis and phospholipase D .......................................................
4.1. Phosphatidylcholine hydrolysis as a source of signaling lipids
4.2. Phosphatidic acid as a signaling molecule ............................................... . . .....
4.3. Receptor-coupled activation of phospholipase D
4.4. Molecular nature and mechanism of regulation o
4.5. A model for recept
nvolving a phospholipase
..................................................
cascade .................
5. Phospholipid kinases and
5.1. Phosphatidylinositol4,5-bisphosphate
trisphosphate as potential signal molecules .........._.......
........................... .................
5.2. Phosphatidylinositol 3-kinase: its structure, regulation and biological relev
6. Future directions .....................................................................................................

.............
References ........................................

252
252
253
254

Chapter 10. Adipose tissue and lipid metabolism
D.A. Bemlohr and M.A. Simpson .............................................................................................

257

1.
2.

1.
2.

........
.,...............,................................................
Introduction.
.........
Adipose development .................................................................
2.1. Development of white and brown adipose tissue in vivo ........................................
2.2. In situ models of adipose conversion ......................................................................

3.1.
3.2.

Lipid delivery to adipose tissue .................................
Fatty acid uptake and

3.5.2. Glucagon .................................

3.6.

Brown fat lipid metabolism ................
3.6.1. Triacylglycerol synthesis and

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262
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270
................... 27 1
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.........................................
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274


4.

5.

Molecular cell biology of adipose tissue
....................
4.1. Energy balance and basal metabolic rate .........................................
4.2. The hypothalamus-adipocyte circuit and the ob gene
4.3. Cytokine control of adipose lipid metabolism ........................................................
Future directions .................................................

...................

.................................................................

Chapter 11 . The eicosanoids: cyclooqgenase. lipoxygenase. and epoxygenase pathways
W.L. Smith and F.A. Fitzpatrick ................................................................................................

275
275
276
278
279
280

283

283
283
285
285
2. Prostanoid biosynthesis
285
285
287
2.3. Prostaglandin endoperoxide H2 (PGH2) formation .................................................
288
2.4. Physico-chemical properties of PGH synthases .
289
2.5. PGH synthases and non-steroidal anti-inflamma

....................................
290
2.6. PGH synthase active site ...............................................................
290
2.7. Regulation of PGHS-1 and PGHS-2 gene expression .............................................
292
2.8. PGH2 metabolism ..........................................................................
293
3. Prostanoid catabolism and mechanisms of action ..............................................................
293
3.1. Prostanoid catabolism ..............................
..................
293
3.2. Physiological actions of prostanoids .
294
3.3. Prostanoid receptors ..........................
295
4. Hydroxy- and hydroperoxy-eicosaenoic acids a
trienes .......................................
295
4.1. Introduction and overview ......................................................................................
296
4.2. Mechanism of leukotriene biosynthesis in human neutrophils ...............................
298
4.3. The enzymes of the 5-lipoxygenase pathway .......................................................
299
4.4. Regulation of leukotriene synthesis ..............................................
300
301
4.6. Biological activities of leukotrienes ..............................................

5 . Epoxygenase products .......
....................................
302
302
5.1. Introduction .............................................................................................................
303
5.2. Structures, nomenclature, and biosynthesis
304
5.3. Occurrence of epoxyeicosatrienoic acids ................................................................
304
5.5. Biological actions of epoxygenase-derived EpETrEs and HE
................ 305
306
6. Future directions .....
306
References .................................................................................................................................

...........................

Chapter 12. Sphingolipids: metabolism and cell signalling
AM . Merrill. Jr. and C.C. Sweeley ..........................................................................................

1.

Introduction .......................................................................................................................
1.1. Biological significance of sphingolipids .................................................................
1.2. Structures and nomenclature of sphingolipids ........................................................

309
309

309
310


XVII
2.

Chemistry and distribution ................................................................................................
2.1. Sphingoid bases ...........................................
........................
2.2. Ceramides .......................................................................................................
2.3. Phosphosphingolipids .......

313
313
314
314
315
315
316
....................................
318
318
............................. 318
318
319
322
322
3.3. Neutral glycosphingolipids ......._.
........

323
3.4. Gangliosides ............................................................................................................
324
3.5. Sulfatoglycosphingolipids ....
327
4. Sphingolipid catabolism ....................................................................................................
327
4.1. Sphingomyelin ...
328
329
4.3. Ceramide
330
330
5. Regulation of sphingolipid metabolism.
33 I
5.1. Embryogenesis ........................................................................................................
33 1
33 1
5.2. Neural development and function ...............................
5.3. Physiology (and pathophysiology) of the intestinal tract .........................................
332
5.4. Male-female differences in kidney sphingolipids ................................................... 333
333
5.5. Leukocyte differentiation ...... ......
333
334
334
..............................
335
6.2. Hydrolysis to bioactive lipid backbones .....................

............,.....
................................................ 336
6.2.1. Ceramide
336
6.2.2. Sphingoid bases ....,......._....
................. ...........
337
6.2.3. Sphingosine 1-phosphate ...........................................................................
338
7. Future directions .......................................................................
338
.............................................
References .....................
Chapter 13. Isoprenoids, sterols and bile acids
P.A. Edwards and R. Davis ......................................................................................................
1.

Introduction ..._...............
.....................................
1.1. The sterol biosynthetic pathway
2.1.
2.2.

........................................................

............................................

Non-sterols .......
Sterols .......................................................................................................
2.2.2.

Bile acids ........................................................

341
341
342
343
343
343
343
344


XVIII

3.

2.2.3. Steroid hormones ......
Cholesterol and bile acid synthesis ...
...........................................
3.1. Enzyme compartmentalization
3.2. Mutations in the human chole
3.3. Regulation of cellular cholesterol homeostasis; an overview.. ................................

4.

3.5. Post-transcriptional regulation of HMG-Co reductase .....
Oxysterols ...................

7.

Regulation of bile acid synthesis ..................

8.
9.

Isoprenylation of proteins ...............................................................................
Future directions ...................

.................

......,.....................................................................................,......
Chapter 14. Lipid metabolism in plants
K.M. Schmid and J.B. Ohlrogge .................................................................................................

1.
2.

3.

4.

5.

6.
7.

8.

9.

344
344
344
346
346
348
35 1
353
353
354
355
355
356
357
357
359
360

363

..................... 363
364
................... 364
367
368
368
368
368
369

3.2. Desaturation of acyl-ACPs ....................................................................
370
3.3. Acyl-ACP thioesterases.. .......
370
370
37 1
37 1
37 1
372
5.3. Traffic between prokaryotic and eukaryotic pathways: 16:3 and 18:3 plants ......... 372
372
Glycerolipid synthesis pathways ......................................................................
374
6.1. Glycerolipids as substrates for desaturation ............................................................
374
Sterol, isoprenoid and
Lipid storage in plants ........................................................................................................
375
376
8.1. Lipid body structure and biogenesis .
8.2. Seed triacylglyc
377
377
8.3. The pathway of
8.4. Challenges in triacylglycerol synthesis ...................................................
379
Progress in plant lipid
379
379
9.1. Mutants in lipid

XIX
9.2. Arabidopsis mutants have allowed cloning of desaturases and elongases ..............
10. Design of new plant oils ............................................................
10.1. Design of new edible oils.
......................................................
10.1.1. Improvements in nutritional value and stability
10.1.2. Alternatives to hydrogenated vegetable oils ...............................................
10.2. Design of new industrial oils...........................................
10.2.1. High lauric oils ....
11. Future prospects ...................
References

382
383
383
383
384
385
386
387
387
388

Chapter IS. Lipid assembly into cell membranes
D.R. Voelker ...............................................................................................................................

391

Introduction ...............................,..................................
The diversity of lipids
Methods to study intra- and inter-membrane lipid transport
......................*.....
3.1. Fluorescent probes
3.2. Spin labeled analogs ...........................................
3.3. Asymmetric chemical modification of membranes .................................................
3.4. Phospholipid transfer proteins .........................................
...........................
3.5. Rapid plasma membrane isolation ........
3.6. Organelle specific lipid metabolism .....,.....................................................
Lipid transport processes .................................
..........................
4.1. Intramembrane lipid translocation and model membranes ............
4.2. Intramembrane lipid translocation and biological membranes ................................

References .................................................

39 1
391
394
394
394
396
397
398
399
399
399
40 1

40 I
402
406
407
408
42 1
422

Chapter 16. Assembly of proteins into membranes
R.A.F. Reithmeier .........._._........................,..................................,........................ .....................

425

1.
2.
3.

4.

4.2.2.

Eukaryotes ...............................

4.3. I .

Transport in prokaryotes ...... ....

......................

........................

........................................

..........................

1.

Organization of membrane proteins ................ .................................................. ............
1.1. Classification of membrane proteins .....................................................
...................
1.2. Membrane protein structure and energetics ..............................................
1.3. Assembly of membrane proteins .............................................................................
Secretion of proteins and the signal hypothesis .....................................
2.1. The Palade secretion pathway ................
......................................................
.
.
.
.
.
.
.
.
.
.
.
.
.
......................................
2.2. The Blobel signal hypothesis ..

2.3. In vitro translation and translocation systems ....
.......................................
2.4. The Milstein experiment: secreted proteins are made with an amino-terminal
signal sequence ...... .................................................... .
..........................
.....................................................
2.5. Signal sequences ...................................
I

2.

425
425
427
429
43 1
432
432
434
436
436


3.

The targeting and translocation machinery.......

4.

Translocation components ............................................................ ............. ......

Ribosome-binding proteins
Signal peptidase ......................................................................................... ........
Biosynthesis of type I membrane proteins .........................................
4.1. IgM and the relationship between the biosynthesis of secreted proteins and
single span TM proteins ......................................................................
4.2. VSV glycoprotein .......

439
439
440
441
442
443
445

3.3.
3.4.
3.5.

445
447
448
.....................
449
449
449
5.2. Asialoglycoprotein receptor ...
45 1
5.3. Sucrase-isomaltase ..................................................................,........
45 1

45 1
452
452
452
453
454
454
455
7.6. Cleaved signal sequences in multi-span membrane proteins ....................... ............ 455
456
8. Glycosylation of proteins.. .....................................................
456
8.1. N-Glycosylation
.....................................................................
457
8.2. Processing of the oligosaccharide chain ......................
...................... * ......................... .... 459
8.3. 0-Glycosylation .....
459
459
9.1. Fatty acylation ...._._.....
460
460
10. Protein folding and exit from the ER ..............................................................
460
46 1
46 1
10.3. Assembly of multisubunit systems ........
462
10.4. Exit from the ER ......................................................................................................

........................... ,............................ 462
11. Vesicular transport and targeting of proteins ......
462
1I . 1. Vesicles move proteins between organelles ............................
464
11.2. Role of GTP-binding proteins .................................................................................
466
1 1.3. KDEL, an ER localization signal ........................ .....................
11.4. Golgi localization .......................
...................................... ....... 466
467
1 1.5. Lysosomal targeting .................................................................................................
.... 468
1 1.6. Protein sorting in epithelial cells
469
12. Future directions ................................................................................................................
469
References
................
....................
~

I


Chapter 17. Structure, assembly and secretion of lipoproteins
R.A. Davis and J.E. Vance........................................................................................................

1.
2.

Overview: structure and function of plasma lipoproteins ..................................................
Assembly and secretion of apolipoprotein B-containing lipoprote
2.1. Apoproteins of VLDLs and chylomicrons ...............................................................
2.2. Intracellular route of apo B secretion ..................................
2.3. Apo B structure ...
...............................................
2.3.1. Apo B is an unusually large amphipathic protein ......................................
2.3.2. Motifs shared with vitellogenin, a primordial apolipoprotein ....................
2.4. Transcriptional regulation of apo B synthesis ......
2.4.1. Tissue specificity of expression of apo B
2.4.2. The apo B gene: transcription regulatory elements ....................................
...............................................
2.4.3. Editing of apo B mRNA
2.5. Post-translational regulation of a
.........................................
.........................
2.5.1. Co- and post-translational processing of apo B
2.5.2. Regulation of apo B secretion by lipid supply ...........................................
2.5.3. Regulation of apo B secretion by translocational efficiency ...

......................................................
.........................
......................................................
Chapter 18. Dynamics of lipoprotein transport in the human circulatory system
P.E. Fielding and C.J. Fielding .................................................................................................

2.

3.

473
473
474
474
476
477
477
477
478
478
478
480
48 1
48 1
48 1
483
484
485
486
487
487
490
49 1
492

495

.................................... 495
.....................................,..................

497
Lipoprotein lipase and the metabolism of lipop
497
2.1. Initial events .................................
498
2.2. The structure of lipoprotein lipase
500
2.3. Synthesis, regulation and transport of
501
2.4. Structure of the LPL-substrate complex at the vascular surface ...............
.........................
503
2.5. Kinetics of the LPL reaction and the role of albumin.
504
2.6. Later metabolism of chylomicron
505
2.7. Physiological regulation of LPL ..........................................
2.8. Congenital lipoprotein lipase deficiency. .......
....................................
505
506
HDL and plasma cholesterol metabolism
3.1. The apo A1 cycle ................................
..............................................
506
507
3.2. The structure of apo A1 ................
................................... 509
3.3. Origin of 1ecithin:cholesterol acyltransferase.
......................... 509

3.4. Structure/function relations in LCAT .......................
509
3.5. Substrate specificity of LCAT.................................................................................
511
3.6. Hepatic lipase and its role in HDL metabolism .............. ......
51 1
3.7. Evidence from transgenic mice on the functions of apo A1 ......................


XXII

4.

3.9. Congenital LCAT defici
Reactions linking metabolism i

......................................

4.2. Phospholipid transfer protein (PLTP) .....................................................................
4.3. Cholesteryl ester transfer protein (CETP) ...........
5. Summary and future directions
Acknowledgment ..................................................................................
References .......
Chapter 19. Removal of lipoproteins from plasma
W.J. Schneider ............................... .......................................

1.
2.

5.

6.

.......................................... .......... 517
~

Introduction .......................................................................................................................
Removal of LDL from the circulation
2.1. Receptor-mediated endocytosis. ..............................................................................
2.2. The LDL receptor pathway ................................................
2.3. Familial hypercholesterolemia: biochemical basis and clinical consequences of
LDL receptor dysfunction .......................................................................................
2.3.1. Biosynthesis and structure of the LDL receptor ..........
2.4. Molecular defects in LDL receptors of patients with familial
hypercholesterolemia ............................................................................
2.4.1. The gene for the human LDL receptor .......................................................
2.4.2. Four groups of LDL receptor mutations ....................................................
3.1.
3.2.

Catabolism of chylomic
Catabolism of VLDL in

......................

HDL as a transport vehicle ................................................................................................
Atherosclerosis .....
6.1. Macrophage
6.2. LDL metabolism by serosal mast cells..

References ..._..

Subject index ...................................

~

512
512
513
513
514
514
515
515
515

..........................................................................................

517
519
520
521
522
523
525
525
525
528
528
530
530
53 1

53 1
532
534
535
536
537
538
538
540
543


D.E. Vance and J.E. Vance (Eds.), Biochemistry of Lipids, Lipoproteins and Membranes
0 1996 Elsevier Science B.V. All rights reserved

CHAPTER 1

Physical properties and functional roles of lipids in membranes
PIETER R. CULLIS1,2,DAVID B. FENSKE' and MICHAEL J. HOPE2,3
'Department of Biochemistry and Molecular Biology, Faculty of Medicine, University of British Columbia,
Vancouver, B.C., V6T 123, Canada, 21nex Pharmaceuticals Corp., 1779 W. 75th Avenue, Vancouver, B.C.,
V6P 6P2, Canada and 'Division of Dermatology, Faculty of Medicine, University of British Columbia,
Vancouver, B.C., V5Z IL7, Canada

1. Introduction and overview
Biological membranes contain an astonishing variety of lipids. As detailed throughout
this book, generation of this diversity requires elaborate metabolic pathways. The lipid
compounds representing the end products of these pathways must bestow significant
evolutionary advantages to the cellular or multicellular systems in which they reside,
implying particular functional roles for each component. However, clarification of the

functional roles of individual lipid species has proven a difficult problem. Here we present a synopsis of the physical properties of lipid systems and indicate how they may relate to the functional capacities of biological membranes.
The major role of membrane lipids has been understood in broad outline since
the early experiments of Gorter and Grendell [I], who extracted lipids from the erythrocyte membrane and measured the areas these lipids were able to cover as a monolayer at
an air-water interface. This work led to the conclusion that the erythrocytes contained
sufficient lipid to provide a bilayer lipid matrix surrounding the red blood cell. This bilayer lipid organization, which provides a permeability barrier between exterior and interior compartments, has remained a dominant theme in our understanding of the organization and function of biological membranes. Subsequent observations that such bilayers
are fluid, allowing rapid lateral diffusion of lipid and protein in the plane of the membrane, and that membrane proteins are often inserted into and through the lipid matrix,
have further contributed to our present understanding of membranes, resulting in the
Singer and Nicholson [2] fluid mosaic model, a refined version of which is shown in Fig.
1.
The ability of lipids to assume the basic bilayer organization is dictated by a unifying
characteristic of membrane lipids namely, their amphipathic character, which is indicated
by the presence of a polar or hydrophilic (water loving) head group region and non-polar
or hydrophobic (water hating) region. The chemical nature of these hydrophilic and hydrophobic sections can vary substantially. However, the lowest-energy macromolecular
organizations assumed in the presence of water have similar characteristics, where the
polar regions tend to orient towards the aqueous phase, while the hydrophobic sections
are sequestered from water. In addition to the familiar bilayer phase, a number of other


2

C W

Fig. 1. The topography of membrane protein, lipid and carbohydrate in the fluid mosaic model of a typical
eukaryotic plasma membrane. Phospholipid asymmetry results in the preferential location of PE and PS in the
cytosolic monolayer. Carbohydrate moieties on lipids and proteins face the extracellular space. AV represents
the transmembrane potential, negative inside the cell.

macromolecular structures are compatible with these constraints. It is of particular interest that many naturally occurring lipids prefer non-bilayer structures in isolation.
The fluidity of membranes depends on the nature of the acyl chain region comprising
the hydrophobic domain of most membrane lipids. Most lipid species in isolation can

undergo a transition from a very viscous gel (frozen) state to the fluid (melted) liquidcrystalline state as the temperature is increased. This transition has been studied intensively, since the local fluidity, as dictated by the gel or liquid-crystalline nature of membrane lipids, may regulate membrane-mediated processes. However, at physiological
temperatures most, and usually all, membrane lipids are fluid; thus, the major emphasis
of this chapter concerns the properties of liquid-crystalline lipid systems. As indicated
later, the melted nature of the acyl chains depends on the presence of cis double bonds,
which can dramatically lower the transition temperature from the gel to the liquidcrystalline state for a given lipid species.
The ability of lipids to self-assemble into fluid bilayer structures is consistent with two
major roles in membranes: establishing a permeability barrier and providing a matrix
with which membrane proteins are associated. Roles of individual lipid components may
therefore relate to establishing appropriate permeability characteristics, satisfying insertion and packing requirements in the region of integral proteins (which penetrate into or
through the bilayer), as well as allowing the surface association of peripheral proteins via
electrostatic interactions. All these demands are clearly critical. An intact permeability