Membrane Fluidity (Biomembranes). Questo articolo non è disponibile.Membrane Fluidity (Biomembranes)

The aim of this book is to bring together in one volume the current research and thought on the concept of membrane fluidity as a biological phenomenon. The invited articles are intended to review recent develop­ ments in the areas of membrane research covered and to summarize the current concepts and theories in those areas. The authors have been given ample opportunity to present their thoughts and speculation on membrane fluidity and related phenomena in a more expanded form than is usually possible in reviews of this type. It is hoped that this approach will have a stimulating effect on research and theoretical development in the biomem­ brane field. The chapters in this book are arranged in three sections, the first of which covers physical studies of membrane fluidity and related phenomena on the molecular level. Included are chapters on intermolecular hydrogen bonding between membrane lipids, thermal analysis of membranes, appli­ cation of fluorescence and NMR spectrometry to the study of membrane fluidity, and the effect of drugs and other compounds on membrane stability and fluidity. The second section deals with the regulation of membrane fluidity in microorganisms, plants, and higher organisms by factors such as tem­ perature, fatty acid chain length, lipid desaturation, and polar head group structure.

I. Physical Studies of Membrane Fluidity and Related Phenomena.- 1 Intermolecular Hydrogen Bonding between Membrane Lipids.- I. Introduction.- II. Evidence for Intermolecular Hydrogen Bonding.- A. Phospholipids.- B. Sphingolipids.- C. Glyco-glycerolipids.- D. Cholesterol.- III. Influence of Intermolecular Hydrogen Bonding on Membrane Structure.- A. Lamellar to Nonlamellar Phase Transitions.- B. Phase Separation or Domain Formation.- C. Interactions with Proteins.- IV. Control Mechanisms for Membrane function.- A. Regulation of Hydrogen Bonding by Change in Environment.- B. Regulation of Hydrogen Bonding by Enzymatic Alteration of Lipid Composition.- V. Summary.- VI. References.- 2 Thermal Analysis of Membranes.- I. Introduction.- II. Thermal Analysis.- A. Techniques.- B. Application of Differential Thermal Analysis and Differential Scanning Calorimetry to the Study of Membranes.- C. Thermal Analysis and Membrane Fluidity.- III. Analysis of Model Membranes.- A. Factors Which Affect the Transition Temperature of Model Membranes Containing One Phospholipid.- B. The Interaction of Other Compounds with Lipids in the Bilayer.- C. Mixtures of Lipids in Model Membranes — Phase Diagrams.- IV. Biological Membranes.- A. Membranes from Prokaryotic Cells.- B. Membranes from Eukaryotic Cells.- V. Summary.- VI. References.- 3 Fluorescence Polarization Studies of Membrane Fluidity: Where Do We Go from Here?.- I. Introduction.- II. Theoretical Perspective.- A. Polarization and Fluidity.- B. Dynamics of Probe Motion.- C. Relationship of Fluorescence Lifetime and Measured Anisotropy.- III. Fluorescence Polarization in Heterogeneous Systems.- A. A Dilemma.- B. Strategies for Localization of Probes in Heterogeneous Systems.- IV. Asymmetry.- A. The Surfaces of Serum Lipoproteins as Model Monolayers.- B. Impermeable Probes.- C. A Mathematical Approach.- V. Lateral Organization.- A. Structural Basis for Lipid Organization.- B. A Selection of Biological Evidence in Support of Membrane Domains.- C. Fatty Acids and Membrane Domains.- D. Probe Partition.- VI. Resonance Energy Transfer.- VII. Fluidity and Mobility.- VIII. Summary.- IX. References.- 4 Conformational and Motional Properties of Lipids in Biological Membranes as Determined by Deuterium Magnetic Resonance.- I. Introduction.- II. Properties of Membrane Lipids.- III. Deuterium NMR of Ordered Systems: Observables and Observing.- IV. Acholeplasma laidlawii B: A Simple Biological Membrane.- V. Dependence of Molecular Ordering on Position along the Fatty Acyl Chain.- VI. The Spectra of Gel-State Lipid.- VII. The Use of Spectral Moments in Analysis.- VIII. The Influence of Cholesterol.- IX. Protein-Lipid Interaction.- X. Effects of Membrane-Active Drugs.- XI. Prognosis.- XII. References.- 5 Fluidity of Cell Membranes in the Presence of Some Drugs and Inhibitors.- I. Introduction.- A. Fluorescence Measurements.- B. Macroscopic Viscosity Measurements.- C. ESR Spectroscopy Using Spin Labels.- D. Differential Scanning Calorimetry.- E. NMR Spectroscopy.- F. Infrared Spectroscopy.- G. Raman Spectroscopy.- H. Addendum.- II. Action of Local Anesthetics on Red Cell Membrane.- III. Action of Benzoic Acid Esters on Red Cell Membrane.- IV. Comparison of Tricyclic Drugs: Phenothiazines vs. Antidepressive Substances on Red Cell Membrane.- V. Localized Change of Membrane Fluidity vs. Average Change.- VI. Site of Action of the Transport Inhibitor Phloretin at the Red Cell Membrane.- VII. Diethylpyrocarbonate in Probing Lipid-Protein Interaction.- VIII. Structural Change of Mitochondrial Membrane and of Oligomycin-Sensitive ATPase from Mitochondria in the Presence of Uncouplers of Oxidative Phosphorylation.- IX. Summary and Outlook.- X. References.- 6 Lipid Bilayer Stability in Biological Membranes.- I. Introduction.- II. Different Factors Affecting Lipid Molecular Shape.- A. Intrinsic Properties of the Lipid Molecule.- B. Extrinsic Factors.- III. Lipid Molecular Shape and Membrane function.- A. Lipid Regulation Mechanisms.- B. Protein-Lipid Interactions.- C. Asymmetry.- D. Electrical Forces across the Membrane.- E. Transfer of Macromolecules across the Membrane.- F. Other Biological Processes and Bilayer Stability.- IV. References.- II. Regulation of Membrane Fluidity.- 7 The Relationship between Membrane Lipid Fluidity and Phase State and the Ability of Bacteria and Mycoplasmas to Grow and Survive at Various Temperatures.- I. Introduction.- II. Membrane Lipid Fluidity and Its Measurement.- A. The Concept of Fluidity in Lipid Bilayers.- B. The Physical Measurement of Membrane Lipid Fluidity and Phase State.- III. Relationship between Membrane Lipid Fluidity and Phase State and Cell Growth.- IV. Relationship between Membrane Lipid Fluidity and Phase State and Heat and Cold Sensitivity.- A. Susceptibility to Cold Shock.- B. Susceptibility to Heat Shock.- V. Possible Molecular Bases for the Relationships between Membrane Lipid Fluidity and Phase State and Cell Growth and Survival.- A. Growth and Survival at Low Temperatures.- B. Growth and Survival at High Temperatures.- C. “Homeoviscous” versus “Homeophasic” Regulation.- VI. Conclusions.- VII. References.- 8 Thermal Control of Fatty Acid Synthetases in Bacteria.- I. Introduction.- II. Regulation of Fatty Acid Composition of Coryneform Bacteria.- A. Cellular Fatty Acid Composition.- B. Metabolic Alteration of Cellular Fatty Acids.- C. Mechanism of Biosynthesis of Unsaturated Fatty Acids.- III. Comparative Aspects of Fatty Acid Synthetases.- IV. Regulation of Fatty Acid Synthetase of Brevibacterium ammoniagenes.- A. Mass Fragmentographic Assay of Fatty Acid Synthetase.- B. Effect of Temperature on Fatty Acid Spectra.- C. Effect of Substrate Concentration on Fatty Acid Spectra.- D. Structure of Fatty Acid Synthetase.- V. Fatty Acid Synthetases from Other Strains of Coryneform Bacteria.- VI. Summary.- VII. References.- 9 Regulation and Pathways of Membrane Lipid Biosynthesis in Bacilli.- I. Introduction.- II. Fatty Acid Metabolism in Bacilli.- A. Fatty Acid Composition and Biosynthesis.- B. Effects of Culture Growth Temperature on Fatty Acid Composition.- C. Temperature-Mediated Mechanisms for the Regulation of Fatty Acid Desaturation in B. megaterium 14581.- III. Membrane Phospholipid Metabolism in Bacilli.- A. Phosphatidylglycerol Biosynthesis.- B. Phosphatidylethanolamine Biosynthesis.- IV. Effects of Perturbations in Membrane Fluidity on Metabolic Processes in Bacilli.- A. Effects on Desaturation.- B. Effects on Phospholipid Biosynthesis.- C. Effects on DNA Synthesis.- V. Summary.- VI. References.- 10 The Regulation of Membrane Fluidity in Bacteria by Acyl Chain Length Changes.- I. Introduction.- II. Regulation of Membrane Fluidity in Micrococcus cryophilus.- A. Effect of Growth Temperature on Lipid Composition.- B. Effect of Temperature on Desaturase Activity.- C. Determination of Membrane Fluidity.- D. Biochemical Mechanism of Acyl Chain Length Regulation.- III. Temperature Regulation of Acyl Chain Composition in E. coli.- IV. A Comparison of Temperature Regulation in M. cryophilus with That in Other Bacteria.- V. Summary.- VI. References.- 11 The Control of Membrane Fluidity in Plasmalogen-Containing Anaerobic Bacteria.- I. Introduction.- II. Phase Behavior of Ether Lipids.- III. Anaerobic Bacteria—Ether Lipids and Membrane Fluidity.- A. Spirochetes.- B. Gram-Negative Anaerobic Rods.- C. Gram-Negative Anaerobic Cocci.- D. Gram-Positive Spore-Forming Anaerobes.- E. Mycoplasma.- IV. Conclusions.- V. References.- 12 Regulation of Membrane Fluidity by Lipid Desaturases.- I. Introduction.- II. Desaturases of Eukaryotes.- A. Acyl-CoA Desaturation.- B. Phospholipid Desaturation.- III. Control of Desaturase Systems.- A. Nutritional Control.- B. Control at Level of Enzyme Synthesis.- C. Control of Changes in Membrane Fluidity.- IV. Conclusions.- V. References.- 13 The Regulation of Membrane Fluidity in Tetrahymena.- I. Introduction.- II. General Description of the Tetrahymena Cell.- III. Membrane Lipid Metabolism in the Absence of Environmental Stress.- IV. Alteration of Lipid Metabolism in Environmentally Stressed Cells.- A. Stress Studies Applied to Tetrahymena.- B. Studies on the Effects of Low Temperature on Tetrahymena.- V. Summary.- VI. References.- 14 Control of Membrane Fluidity in Fusarium.- I. Introduction.- II. Phospholipid Biosynthesis.- III. Unsaturated Fatty Acids.- IV. Sterol Biosynthesis.- V. Summary.- VI. References.- 15 Regulation of Hepatic Phospholipid N-Methylation.- I. Introduction.- II. Assay of Phospholipid Methylation.- III. Regulation of Phospholipid Methylation by Substrate Availability.- IV. Inhibitors of Phospholipid Methylation.- V. Effect of Diet on Phospholipid Methylation.- A. Choline-Methionine Deficiency.- B. Vitamin B12 Deficiency.- C. Folate Deficiency.- VI. Physiological Role of Phospholipid Methylation.- A. Relation to Membrane Lipid Composition.- B. Relation to Biological Signal Transmission.- C. Relation to the Supply of One-Carbon Units.- VII. References.- III. Correlation of Membrane Fluidity and Physiological Activity.- 16 Fluidity of Membrane Lipids.- I. General Overview.- II. Fluidity Concepts.- A. Expansion of Liquids.- B. Additive Contributions of Acyl Chains to Fluidity.- III. Membrane Functions Limited by Fluidity: Development of a Model.- A. Growth of Fatty Acid Auxotrophs.- B. Additive Responses to Nutrient Acids.- C. Additive Effects of Membrane Acyl Chains.- D. Functionality Factors.- IV. Correlations with Fluidity.- A. Melting Points of Free Fatty Acids and Phospholipids.- B. Correlation of Chemical, Physical, and Biological Values.- V. Selective Responses to Acyl Chain Structure.- A. Selective Events vs. Fluidity.- B. Cyclic Nucleotide Prevents Selective Responses.- C. Fluidity of Different Isomers.- VI. Interpretations and Conclusions.- A. Cell Requirements for Unsaturated Fatty Acids.- B. Possible Roles for Cyclopropane Acids.- C. Directions for Future Research.- VII. Summary.- VIII. References.- 17 Membrane Lipid Adaptation in Yeast.- I. Introduction.- II. Lipid Mutants.- A. Introduction.- B. Type I Mutants.- C. Type II and Type III Mutants.- III. Lipids and Membrane-Bound Enzymes.- A. Introduction.- B. Cytochrome Oxidase and ATPase.- C. Arrhenius Plots of Membrane-Bound Enzymes.- IV. Temperature and Lipids.- V. Anaerobic Growth and Lipids.- A. Introduction.- B. Plasma Membranes.- C. Mitochondrial Membranes.- D. Membrane Fluidity.- VI. Summary.- VII. References.- 18 The Dynamic State of Membrane Lipids: The Significance of Lipid Exchange and Transfer Reactions to Biomembrane Composition, Structure, Function, and Cellular Lipid Metabolism.- I. Introduction.- II. Definition of Lipid Exchange and Transfer.- III. Mechanisms of Lipid Exchange and Transfer.- A. Exchange or Transfer via Donor-Acceptor Contact.- B. Exchange or Transfer via Aqueous Diffusion.- C. Kinetics of Lipid Exchange and Transfer.- IV. Methods of Studying Lipid Exchange and Transfer.- V. Factors Affecting Lipid Exchange and Transfer.- VI. Proteins Catalyzing Lipid Exchange and Transfer.- A. Phospholipid Exchange Proteins.- B. Sterol Exchange Proteins.- C. Cholesteryl Ester Exchange Proteins.- VII. Lipid Exchange Reactions as an Aid to Studying Membrane Structure and function.- A. Lipid Asymmetry.- B. Flip-Flop.- C. Compositional Change.- VIII. Role of Lipid Exchange and Transfer in Cellular Metabolism.- A. Lipid Transport into Cells.- B. Sterol Efflux from Cells.- IX. Role of Lipid Exchange and Transfer in Modifying and Maintaining Membrane Composition, Fluidity, and function.- A. Membrane-Bound Enzymes and Membrane Fluidity.- B. Membrane-Bound Enzymes and Membrane Fluidity in Pathological States.- X. Maintenance of Boundary Lipid or Lipid Annulus.- XI. Concluding Remarks.- XII. References.- 19 Role of Phospholipid Head Group Structure and Polarity in the Control of Membrane Fusion.- I. Introduction.- II. Polar Head Group Structure and Bilayer Properties.- A. Head Group Conformation, Charge, and Hydration.- B. Modulation of Head Group and Bilayer Properties by Cations.- C. Effective Size of Hydrated Head Groups.- III. Role of Phospholipid Head Groups and Divalent Cations in Model Membrane Fusion.- A. Fusion of Anionic Vesicles by Ca2+ and Mg2+.- B. Influence of Head Group Structure on Ca2+- and Mg2+-Induced Fusion.- C. Interbilayer Contact and Membrane Fusion.- IV. Possible Significance of Head Group Composition and Interconversion in Mammalian Cell Membranes.- A. The Phosphatidylethanolamine-Phosphatidylcholine Balance.- B. Phosphatidylinositol-Polyphosphoinositide Interconversion.- C. Phosphatidylinositol-Phosphatidate Interconversion.- V. Concluding Remarks.- VI. References.- 20 Membrane Fluidity and Receptor Function.- I. Introduction.- II. The Membrane Lipid Fluidity.- A. Overview.- B. The Submacroscopic Presentation.- C. Chemical and Physical Effectors.- D. The Protein Mobility.- III. Receptor Position.- A. Lateral and Vertical Displacements.- B. Plasticity and Capacity.- C. Degradation and Shedding.- IV. Receptor Activity.- A. The Effect of Ligand Binding on the Lipid Microviscosity.- B. Formation of Microaggregates.- C. Collisional Coupling with a Second Messenger.- D. The Effect of Altered Microviscosity—The Optimal Fluidity Hypothesis.- V. Summary.- VI. References.- 21 Glycosphingolipid Domain Formation and Lymphocyte Activation.- I. Introduction.- II. Early Phenomena Observed during Activation.- A. Ligand-Induced Receptor Redistribution.- B. Changes in Cyclic Nucleotide Levels and in Membrane Permeability.- III. Changes in the Fluidity and State of Aggregation of Lymphocyte Membrane Lipids following Binding of Ligands.- A. The Concept of Fluidity.- B. Results of Studies on Lymphocyte Membrane Fluidity after Ligand Binding.- IV. Glycosphingolipids in Membranes.- A. General Properties.- B. Receptor Functions.- C. Sugar Head Group Interactions.- D. Ceramide-Bridge Hydrogen Bonding.- E. Bilayer Leaflet Coupling.- V. Lymphocytes and Glycosphingolipids.- A. Composition.- B. Gangliosides and Modulation of Activation.- C. Lymphocyte Activation by Direct Ganglioside Cross-Linking.- VI. Mechanisms of Glycosphingolipid Involvement in Lymphoid Cell Activation.- A. How Are the Glycosphingolipids Clustered in the Membranes of Ligand-Treated Lymphocytes?.- B. Glycosphingolipid Domain Formation and Effector Mechanisms.- C. Glycosphingolipids and B-Cell Modulation.- VII. Future Directions.- VIII. Summary.- IX. References.- 22 Dynamics of Membrane Lipids during Lymphocyte Stimulation by Mitogens.- I. Introduction.- II. Lipid Composition of Resting Cells: Distribution of Fatty Acids in Phospholipids.- III. Dynamics of Phospholipids.- A. Synthesis and Breakdown of Phosphatidylinositol.- B. Methylation of Phosphatidylethanolamine.- C. Metabolism of Released Arachidonic Acid.- D. Exchange of Fatty Acyl Moieties.- E. Deacylation of Phospholipids.- IV. Lymphocyte Functions and Fatty Acids.- A. Proliferation, Blast Transformation.- B. ATPase and Fluidity.- V. Summary and Conclusions.- VI. References.- 23 Membrane Permeability in Porcine Malignant Hyperthermia.- I. Introduction.- II. Membrane Permeability.- A. Sarcoplasmic Reticulum.- B. Mitochondria.- C. Erythrocytes.- D. Abnormalities in Other Membranes.- III. Transition Temperature.- A. Sarcoplasmic Reticulum.- B. Mitochondria.- C. Membrane Composition.- IV. Sarcoplasmic Calcium.- V. Glycolysis.- VI. Hypothesis.- VII. Summary.- VIII. References.