Membrane Spectroscopy

The last 10 years have seen an enormous growth in our understanding of the molecular organisation of biological membranes. Experimental methods have been devised to meas­ ure the translational and rotational mobility of lipids and proteins, thereby furnishing a quantitative basis for the concept of membrane fluidity. Likewise, the asymmetry of bi­ layer membranes as evidenced by the asymmetric insertion of proteins and lipids has been put on firm experimental ground. At higher molecular resolution it has been possible to provide a detailed pi2ture of the molecular conformation and dynamics of lipids and, to some extent, even of small peptides embedded in a bilayer matrix. Many of these achieve­ ments would not have been possible without the application of modem spectroscopic methods. Since these techniques are scattered in a variety of specialized textbooks the present monograph attempts to describe the key spectroscopic methods employed in present-day membrane research at an intermediate level. There is no question that the elusive detailed structure of the biological membrane demands a multiplicity of experi­ mental approaches and that no single spectroscopic method can cover the full range of physical phenomena encountered in a membrane. Much confusion in the literature has arisen by undue generalizations without considering the frequency range or other limi­ tations of the methods employed. It is to be hoped that the present monograph with its comprehensive description of most modem spectroscopic techniques, will contribute to- .

Contenu

1. Nuclear Magnetic Resonance Studies of the Phospholipid Bilayer Membrane.- I. Introduction.- II. Partially Oriented Molecules.- III. Effects of Motional Restriction on NMR Spectra.- IV. Isotropic Motion in the Presence of Restricted Local Motion: Membrane Vesicles.- V. Membrane Dynamics from NMR Relaxation Measurements.- VI. Merits of Various Spin Probes in Membrane Studies.- VII. Selected Applications of NMR to Membrane Studies.- VIII. Future Prospects.- References.- 2. Electron Spin Resonance: Spin Labels.- I. Introduction.- II. Experimental Methods.- III. Theoretical Basis.- IV. Applications to Membrane Studies.- V. New Developments and Future Trends.- References.- 3. Absorption and Circular Dichroism Spectroscopies.- I. Introduction.- II. Solution Studies.- III. Suspensions of Homogeneous Particles.- IV. Suspension of Biomembranes (Heterogeneous Particles).- References.- 4. Optical Spectroscopy of Monolayers, Multilayer Assemblies, and Single Model Membranes.- I. Introduction.- II. General Considerations and History.- III. Design of Spectroscopic Probes.- IV. Concentration, Orientation, and Location of Chromophores.- V. Monomers, Dimers, and Aggregates.- VI. Energy Transfer.- VII. Lipoid pH-Indicators in Monolayers.- VIII. Lateral Diffusion in Model Membranes.- IX. Electric-Field-Induced Effects.- References.- 5. Fluorescence Spectroscopy of Biological Membranes.- I. Basic Theory.- II. Types of Fluorophores Used in the Study of Membranes.- III. Applications.- References.- 6. Infrared Membrane Spectroscopy.- I. Introduction.- II. Experimental Techniques 1 Spectrophotometric Consideration.- III. Application of IR Spectroscopy to Biological Systems.- IV. Review of Results of IR Membrane Spectroscopy.- References.- 7. Chemical Relaxation Spectrometry.- I. Introduction.- II. Experimental Methods.- III. Theoretical Aspects.- IV. Applications to Membrane Studies.- References.- 8. Raman Spectroscopy of Membrane Constituents and Related Molecules.- I. Introduction.- II. Experimental Methods.- III. The Theoretical Basis of Raman Spectroscopy.- IV. Applications to Membrane Studies.- V. Future Trends.- References.- 9. Low-Angle X-Ray Diffraction.- I. Introduction.- II. Experimental Methods.- III. Theory.- IV. Applications to Membrane Systems.- V. Conclusions.- References.