Membrane Proteins (eBook)

Cover 1
CONTENTS 6
PREFACE 12
Chapter 1. Membrane Protein Assembly in Vivo 18
I. Introduction 18
II. Overview of Membrane Protein Assembly Pathways in Prokaryotic and Eukaryotic Cells 19
III. Membrane Protein Assembly in the ER 20
IV. Membrane Protein Assembly in Escherichia coli 26
V. Membrane Protein Assembly in Mitochondria 27
VI. Membrane Protein Assembly in Chloroplasts 29
VII. Membrane Protein Assembly in Peroxisomes 29
VIII. Conclusions 29
References 30
Chapter 2. Construction of Helix-Bundle Membrane Proteins 36
I. Introduction 36
II. Transmembrane Helix Structure 37
III. Thermodynamic Studies 41
IV. The Contribution of Loops versus Transmembrane Helices 45
V. Forces That Stabilize Transmembrane Helix Interactions 46
VI. Conclusions 59
References 60
Chapter 3. Transmembrane ß-Barrel Proteins 64
I. Introduction 64
II. Structures 66
III. Construction Principles 72
IV. Functions 76
V. Folding and Stability 78
VI. Channel Engineering 80
VII. Conclusions 82
References 83
Chapter 4. Length, Time, and Energy Scales of Photosystems 88
I. Introduction 88
II. Overview of Length Scales in Bioenergetic Membranes 89
III. Managing Lengths in Natural Redox Protein Design 92
IV. Managing Length and Size in Natural Light-Harvesting Design 95
V. Managing Distance in Electron Transfer 99
VI. Managing Proton Reactions in Photosynthesis 110
VII. Managing Diffusion in Photosynthesis 120
VIII. Summary 122
References 123
Chapter 5. Structural Clues to the Mechanism of Ion Pumping in Bacteriorhodopsin 128
I. Introduction 128
II. The Ground, or Resting, State 132
III. Early Photocycle Intermediates (K and L) 135
IV. M Intermediates 138
V. Large-Scale Conformational Changes in the M, N, and O Intermediates 140
VI. Protonation Pathways in the M to N and the N to O Reactions 142
References 144
Chapter 6. The Structure of Wolinella succinogenes Quinol: Fumarate Reductase and Its Relevance to the Superfamily of Succinate:Quinone Oxidoreductases 148
I. Introduction 148
II. Overall Description of the Structure 151
III. The Hydrophilic Subunits 151
IV. Subunit C, the Integral Membrane Diheme Cytochrome b 154
V. General Comparison of Membrane-Integral Diheme Cytochrome b Proteins 156
VI. Relative Orientation of Soluble and Membrane-Embedded QFR Subunits 158
VII. The Site of Menaquinol Oxidation/Menaquinone Reduction 158
VIII. Electron and Proton Transfer and the Wolinella succinogenes Paradox 159
IX. The E-Pathway HypothesisŽ of Coupled Transmembrane Electron and Proton Transfer 162
X. Concluding Remarks 163
References 164
Chapter 7. Structure and Function of Quinone Binding Membrane Proteins 168
I. Introduction 168
II. Structure of Cytochrome bc1 Complex from Bovine Heart Mitochondria 170
III. The Structure of Cytochrome bo3 Ubiquinol Oxidase from Escherichia coli 182
IV. Conclusion 191
References 191
Chapter 8. Prokaryotic Mechanosensitive Channels 194
I. Introduction 194
II. MscL: Structure and Mechanism 202
III. MscS and Other Prokaryotic Mechanosensitive Channels 217
IV. What Makes a Mechanosensitive Channel Mechanosensitive? 221
V. Concluding Remarks 222
References 223
Chapter 9. The Voltage Sensor and the Gate in Ion Channels 228
I. Introduction 228
II. The Voltage Sensor 229
III. The Channel Gate 245
References 255
Chapter 10. Rhodopsin Structure, Dynamics, and Activation: A Perspective from Crystallography, Site-Directed Spin Labeling, Sulfhydryl Reactivity, and Disulfide Cross-Linking 260
I. Introduction to Rhodopsin and Visual Signal Transduction 260
II. The Rhodopsin Crystal Structure: The Inactive State 266
III. Structure and Dynamics of Rhodopsin in Solutions of Dodecyl Maltoside: The Cytoplasmic Surface in the Inactive State 270
IV. Location of the Membrane–Aqueous Interface and the Structure of the Disk Membrane 291
V. Photoactivated Conformational Changes: The Rhodopsin Activation Switch 294
VI. Summary: The Mechanism of Rhodopsin Activation and Future Directions 302
References 303
Chapter 11. The Glycerol Facilitator GlpF, Its Aquaporin Family of Channels, and Their Selectivity 308
I. An Ancient and Long Recognized Channel 308
II. Three-Dimensional Structure of GlpF with Glycerol in Transit 312
III. The Basis for Selectivity through the Channel 316
IV. Roles of Conserved Residues: Functional and Structural 318
V. Stereoselective Preferences of GlpF among Linear Alditols 320
VI. Simulations and Rates of Glycerol Passing through the Channel 321
VII. Simulation and Rates of Water Passage through the GlpF (an AQP) Channel 322
VIII. Insulation against Proton Conduction in AQPs 324
IX. Quaternary Structure of GlpF (and AQPs) 324
X. The Ion Channel in AQP6 a Possible Pore on the Fourfold Axis of AQPs?
XI. GlpF Channel Selectivity for Antimonite 326
XII. Selectivity against Passing Ions or an Electrochemical Gradient 326
XIII. The Various Contributions to Rejection of Proton Conductance 327
XIV. Selectivity for Glycerol versus Water 328
XV. Regulated Ion Channels Formed by Members of the AQP Family 329
References 330
AUTHOR INDEX 334
SUBJECT INDEX 354