Spin Labeling

List of Contributors

Preface


1. Introduction

I. Electron Spin Resonance in Biology

II. Spin Labeling—A Reporter Group Technique

III. Prelude

References


2. General Magnetic Resonance Theory

I. Introduction

II. Principles of Electron Spin Resonance

III. The Magnetic Interactions

IV. Analysis of the ESR Spectra

V. Line Shape Theory

References


3. Theory of Slow Tumbling ESR Spectra for Nitroxides

I. Introduction

II. Theory

III. Applications

Appendix A. General Solutions and Discussion of the Computer Program for Nitroxides

Appendix B. Computer Program for Slow Tumbling Nitroxides in Isotropic Liquids

References


4. Biradicals as Spin Probes

I. Introduction

II. The Triplet State

III. Biradicals with Hyperfine Interactions

IV. Spin Relaxation

V. Conclusions

Appendix A. The Spin Hamiltonian

Appendix B. The Linewidths for a Nitroxide Biradical

References


5. The Chemistry of Spin Labels

I. The Stability of the Paramagnetic Nitroxide Group in Spin Labels

II. The Synthesis of Spin Labels

III. Experimental Procedures for Preparation of Spin Labels

References


6. Molecular Structures of Nitroxides

I. X-Ray Analysis of Single Nitroxide Crystals

II. Experimental Results

III. Conclusions on the Conformations of Nitroxides

IV. ESR Spectra of Single Nitroxide Crystals

References


7. Instrumental Aspects of Spin Labeling

I. ESR Instrumentation and Instrumental Artifacts

II. The Use of Computers to Process Spin Labeling Data

References


8. The Use of Spin Labels for Studying the Structure and Function of Enzymes

I. Introduction

II. Reagents for Spin Labeling Enzymes

III. Laboratory Techniques for Spin Labeling Enzymes

IV. Information Obtainable from Spin-Labeled Enzymes

V. Detailed Studies of Spin-Labeled Enzymes

VI. Future Possibilities

References


9. Spin-Label-Induced Nuclear Magnetic Resonance Relaxation Studies of Enzymes

I. Introduction

II. Nuclear Spin Relaxation

III. Measurement of Relaxation Times

IV. Enzyme Studies

V. Conclusions

References


10. Anisotropic Motion in Liquid Crystalline Structures

I. Classification of Liquid Crystals

II. The Relevance of Spin Probes to the Investigation of Liquid Crystals

III. Anisotropic Motion of Spin Probes in Liquid Crystals

IV. Nitroxide Spin Probe Investigations of Liquid Crystalline Mesophases

References


11. Oriented Lipid Systems as Model Membranes

I. Types of System

II. Nature of the Spectra

III. Applications

IV. Conclusion

References


12. Lipid Spin Labels in Biological Membranes

I. Introduction

II. Molecular Motion in Membranes

III. Characterizing Macroscopic Order

IV. Polarity Profile

V. Measuring the Fraction of Membrane Lipids in the Fluid Bilayer

VI. Lipid-Protein Interactions in Membranes

References


13. Molecular Motion in Biological Membranes

I. Introduction

II. "Fluid" Membranes

III. Lateral Phase Separations

IV. Lateral Diffusion

V. Membrane Function

VI. The Flexibility Gradient

VII. Membrane Fusion

Appendix A. Rotational Correlation Times

Appendix B. Direct Experimental Evidence for a Phospholipid Spin Label Tilt

References

Appendix I. Simulated X-Band Spectra—Isotropic Tumbling

Appendix II. Principal Values of the g and Hyperfine Tensors for Several Nitroxides Reported to Date

Appendix III. Commercial Sources of Spin Labeling Equipment and Supplies

Appendix IV. Practical Considerations for the Calculation of Order Parameters for Fatty Acid or Phospholipid Spin Labels in Membranes

Appendix V. Symbols and Abbreviations

Index