Main description:

We are pleased to present this second volume of a series that has already received much interest. The application of magnetic resonance methods to the study of actual biological systems as contrasted to cell-free samples, although not entirely novel, as demonstrated by Civan and Shporer in Volume I, has taken on new dimensions with the use of phosphorus-31 and carbon-13 NMR in studying cells, tissues, and organelles. The applications of 31 P NMR to such systems is reviewed in this volume, while carbon-13 will be covered in a later one. The use of nitroxide spin labels has grown to the point where it now may be considered a common biological technique. The synthesis and applications of a new class of nitroxides is described in this volume. ESR spectroscopy of paramagnetic ions is a powerful approach to studying molecular and structural details, as the chapter by Boas, Pilbrow, and Smith on the ESR of copper in Volume 1 has shown. In this volume the ESR of molybdenum and iron is treated in a comparable fashion. In the first volume some aspects of 1 H NMR spectroscopy of certain classes of In this volume the high-resolu biological macromolecules were discussed.* tion multinuclear NMR spectra of peptides, including the physiologically significant peptide hormones, are reviewed.

Contents:

1 Phosphorus NMR of Cells, Tissues, and Organelles.- 1. Introduction.- 2. Methods.- 2.1. Oxygenation and Perfusion.- 2.2. 31P NMR for pH Measurements.- 2.3. Saturation Transfer.- 3. Applications.- 3.1. Cellular Suspensions.- 3.2. Muscle.- 3.3. Brain, Liver, and Kidney.- 3.4. Other Systems.- 4. Summary.- References.- 2 EPR of Molybdenum-Containing Enzymes.- 1. Introduction.- 2. Enzymes to be Considered and Their General Properties.- 3. Relationship of Molybdenum to Other Constituents in the Enzymes and its Interactions with These Constituents.- 4. Multiple Species of Mo(V) and the Estimation of EPR Parameters.- 5. General Survey of the EPR Parameters of Mo(V) Species in Enzymes.- 6. Discussion of the Parameters.- 7. Conditions Governing Generation and Interconversion of the Signals.- 7.1. Introduction and Nomenclature; Functional and Desulfo Xanthine Oxidase.- 7.2. Oxidation-Reduction Potentials Associated with Molybdenum in Enzymes.- 7.3. Binding of Anions, Substrates, and Products.- 7.4. Equilibrium between EPR-Detectable Protonated and Deprotonated Forms.- 7.5. Rates of Exchange of the Interacting Protons; Direct " Hydrogen Transfer from the Substrate.- 7.6. Very Rapid Intermediate.- 7.7. Signals from Reactions of Alcohols with Xanthine Oxidases and Dehydrogenases.- 8. Conclusions on Structures and Enzymatic Mechanisms.- 8.1. Structures.- 8.2. Enzymatic Mechanisms.- References.- 3 ESR of Iron Proteins.- 1. Introduction.- 2. Electron Spin Resonance Caused by Iron Proteins.- 2.1. Introduction.- 2.2. Paramagnetic States of Fe Proteins.- 3. Heme Proteins.- 3.1. Hemoglobin.- 3.2. Methemoglobin.- 3.3. Hemichromes.- 3.4. Nitrosylhemoglobins.- 3.5. Myoglobin.- 3.6. Leghemoglobin.- 3.7. Cytochrome c Oxidase.- 3.8. Cytochromes.- 3.9. Cytochromes P450.- 3.10. L-Tryptophan-2,3-dioxygenase.- 3.11. Cytochrome c Peroxidase.- 3.12. Horseradish Peroxidase.- 3.13. Chloroperoxidase.- 3.14. Myeloperoxidase.- 3.15. Catalase.- 3.16. Flavocytochrome b2.- 3.17. Sulfite Oxidase.- 4. Nonheme Proteins.- 4.1. Hemerythrin.- 4.2. Iron Dismutase.- 4.3. Ferritin and Hemosiderin.- 4.4. Transferrins.- 4.5. The Iron-Sulfur Proteins.- 4.6. Protocatechuate 3,4-Dioxygenase.- 4.7. Lipoxygenase.- 4.8. Ribonucleotide Reductase.- 4.9. Uterine Purple Phosphatase.- References.- 4 Stable Imidazoline Nitroxides.- 1. Introduction.- 2. Synthesis of Imidazoline and Imidazolidine Nitroxides.- 2.1. Synthesis of 3-Imidazoline-3-oxide Derivatives.- 2.2. Synthesis of 2,2,4,5,5-Pentasubstituted-3-imidazolines.- 2.3. Synthesis of Imidazolidine Derivatives.- 2.4. Synthesis of 4-Oxoimidazolidine Derivatives.- 3. Properties of Imidazoline Nitroxides and 1 -Hydroxy-3-imidazolines.- 3.1. Stability of Imidazoline Nitroxides in Acid Media.- 3.2. Quaternary Immonium Salts of Imidazoline Nitroxides.- 3.3. Interaction of Imidazoline Derivatives with Nucleophilic Reagents.- 3.4. Interaction of Imidazoline Derivatives with Electrophilic Reagents.- 3.5. Interaction of 4-Haloalkyl-3-imidazoline-3-oxides with Nucleophilic Reagents.- 3.6. Interaction of 4-Dihaloalkyl-3-imidazoline-3-oxides with Nucleophilic Reagents.- 3.7. Properties of Derivatives of Imidazoline Aldehydes and Ketones.- 3.8. Properties of Derivatives of Imidazoline Carboxylic Acids.- 3.9. Imidazoline Nitroxides as Chelating Reagents.- 4. Spectra of Imidazoline Nitroxides.- 4.1. UV Spectra and Visible Spectra.- 4.2. Vibrational Spectra.- 4.3. Mass Spectra.- 5. Magnetic Properties of Imidazoline Nitroxides.- 5.1. NMR Spectra. Regularities of Long-Range Hyperfine Interactions.- 5.2. Complexes of Transition Metals with Imidazoline Nitroxides.- 6. Applications in Analytical and Structural Chemistry.- 7. Imidazoline Spin Labels in Biology.- 8. Syntheses of Some Imidazoline Nitroxides and Important Intermediates.- References.- 5 The Multinuclear NMR Approach to Peptides: Structures, Conformations, and Dynamics.- 1. A Multinuclear Approach.- 1.1. Introduction.- 1.2. Nuclei Studied.- 2. Chemical Shifts.- 2.1. Magnetic Anisotropy.- 2.2. Chemical Exchange.- 2.3. Assignment Methods.- 2.4. Paramagnetic Reagents.- 2.5. Structural and Conformational Sensitivity of Chemical Shifts.- 3. Spin-Spin Coupling Constants.- 3.1. Proton-Proton Couplings.- 3.2. Carbon-Proton Couplings.- 3.3. Carbon-Carbon Couplings.- 3.4. Nitrogen-Proton Couplings.- 3.5. Nitrogen-Carbon Couplings.- 4. Relaxation Times.- 4.1. Measurement of Relaxation Times.- 4.2. Mechanisms of Relaxation.- 5. Concluding Remarks.- References.