Excited States of Proteins and Nucleic Acids

ISBN-13: 9781468418804 / Angielski / Miękka / 2012 / 488 str.

Robert Steiner

Opis

The choice of title for this collective volume reflects the desire of the editors and authors to make clear that, while the bulk of the material is concerned with luminescence, other aspects of the excited state have not been excluded. In the five years which have elapsed since the publication of the classical monograph of Konev, a wealth of new information has ap peared on the emission properties of proteins and nucleic acids. Indeed, since new publications in this area appear to be proliferating in a geometric ratio, this may be the last opportunity to provide a comprehensive summary of the field in a book which is not of prohibitive length. This is what we have attempted to do here. While the orientation of each chapter naturally reflects the interests and point of view of the author, there has been a general effort to present .a critical assessment of existing results and interpretations, rather than a compendium of data with minimal comment. Finally, it should be stressed that the rapid evolution of the subject at the time of writing makes it inevitable that the book will age to some degree over the next few years, although this will occur at differing rates for the various chapters. We can only hope that most of the material in this interim summing-up will prove resistant to the erosion of time and provide a solid foundation for further progress."

Spis treści

1 Some Principles Governing the Luminescence of Organic Molecules.- 1. Introduction.- 2. Spontaneous Emission.- 2.1. Relationship Between Lifetime and Absorption Coefficient.- 2.2. Influence of Multiplicity on Observed Lifetime.- 2.3. Luminescence from Nearby States.- 2.4. Multiple-State Decay: An Example.- 3. Molecular Luminescence Characteristics.- 3.1. The Transition Dipole Moment.- 3.2. Spontaneous Luminescence in Aggregates.- 4. The Adiabatic Approximation.- 4.1. Dependence of Transition Moment on Nuclear Displacements.- 4.2. Effect of Nuclear Displacements on the Emission Spectrum and Lifetime.- 4.3. Numerical Estimates of Vibronic Effects.- 5. Triplet-Singlet Transitions and Selection Rules.- 5.1. The Mixing of ??* and n?* States.- 6. Relaxation Processes in Molecules.- 6.1. Vibrational Relaxation.- 6.2. Electronic Relaxation.- 6.3. Intersystem Crossing.- 6.4. Spin Polarization.- References.- 2 Experimental Techniques.- A Fluorescence Instrumentation and Methodology.- 1. Basic Considerations.- 1.1. General Description of a Spectrofluorimeter.- 1.2. Representation of Spectra.- 1.3. Calculation of Quantum Yields.- 1.4. Polarization Spectra.- 2. Methodology.- 2.1. Instrument Calibration.- 2.2. Correction for Sample Variations.- 2.3. Cuvettes.- 3. Criteria for a Spectrofluorimeter.- 3.1. Sensitivity.- 3.2. Resolution.- 3.3. Sample Compartment.- 3.4. Photomultipliers.- 3.5. Amplifiers.- 3.6. Summary.- References.- B Direct Measurement of Fluorescence Lifetimes.- 1. Introduction.- 2. Instrumentation.- 2.1. Instrument Considerations.- 2.2. Oscilloscope Techniques.- 2.3. Curve Normalization Techniques.- 2.4. Gated Photomultiplier Detection.- 2.5. Single-Photon Counting.- References.- C Phosphorescence Instrumentation and Techniques.- 1. General Instrumentation.- 1.1. Light Choppers.- 1.2. Photomultipliers.- 1.3. Sample-Cooling Devices.- 2. Matrices.- 3. Population of the Triplet State.- 3.1. Spectra.- 3.2. Quantum Yields.- 3.3. Lifetimes.- 3.4. Polarization of Phosphorescence.- References.- 3 The Excited States of Nucleic Acids.- 1. History and Introduction.- 2. Structures, Nomenclature, and Abbreviations.- 3. Excited States of Monomers.- 3.1. Relevance of Low-Temperature Experiments.- 3.2. Emission Spectra and Other Experimental Parameters.- 3.3. Sensitized Phosphorescence Spectra.- 3.4. Wavefunctions of the Excited States.- 4. Excited States of Oligonucleotides and Polynucleotides at Low Temperature.- 4.1. Types of Interactions.- 4.2. Excited States of Dinucleotides.- 4.3. Excited States of Polynucleotides.- 5. Excited States at Room Temperature.- 5.1. Energy Levels.- 5.2. Nonradiative Rates in Aqueous Solution.- 5.3. Triplet-State Molecules in Aqueous Solution.- 5.4. Temperature Dependence of Fluorescence.- 5.5. Speculations about Fluorescence Quenching and Temperature Effects.- 6. Excited-State Precursors of Photoproducts.- 6.1. Photohydrates.- 6.2. The Cytosine-Thymine Adduct.- 6.3. Photodimers of Pyrimidines.- 6.4. Sensitized Pyrimidine Dimers in Polynucleotides.- 7. Energy Transfer in Polynucleotides.- 7.1. General Considerations.- 7.2. Theory of Energy Transfer.- 7.3. Förster Energy Transfer.- 7.4. Experiments and Calculations.- 8. Transfer RNA.- 8.1. The Role of Odd Bases.- 8.2. tRNAPhe Studies.- References.- 4 Fluorescent Protein Conjugates.- 1. Introduction.- 2. Chemistry of Conjugation.- 2.1. Functional Groups in Proteins and in the Label.- 2.2. Dye Structures.- 3. Experimental Procedures for Labeling.- 3.1. Conditions of Labeling.- 3.2. Isolation of the Labeled Conjugate.- 3.3. Determination of the Degree of Labeling.- 3.4. Fractionation According to the Degree of Labeling.- 4. Effect of the Label on the Properties of the Protein.- 5. Excitation and Emission Spectra.- 5.1. Spectral Data.- 5.2. Changes Due to Alterations in Environment of the Dye Molecule.- 5.3. Electronic Mechanisms Responsible for Changes.- 5.4. Changes Due to Photochemical Reactions.- 6. Lifetime, Decay Time, and Quantum Yield.- 7. Energy Transfer.- 8. Polarization of Fluorescence.- 9. Visible Tracing.- 9.1. Coons Fluorescent Antibody Technique.- 9.2. Quantitative Precipitation Test.- 9.3. N-Terminal Analysis.- 10. Noncovalently Bound Labels.- References.- 5 The Luminescence of the Aromatic Amino Acids.- 1. Introduction.- 2. Excitation of the Aromatic Amino Acids.- 2.1. Excitation by Near-Ultraviolet Radiation: Ultraviolet Absorption Spectra.- 2.2. Excitation by Higher-Energy Radiation.- 3. Environmental Effects upon the Fluorescence of the Aromatic Amino Acids.- 3.1. Temperature.- 3.2. Physical State.- 3.3. Solvent.- 4. Fluorescence Quantum Yields and Lifetimes for the Aromatic Amino Acids.- 5. Fluorescence of Derivatives of the Aromatic Amino Acids.- 5.1. Tryptophan Derivatives.- 5.2. Tyrosine Derivatives.- 5.3. Phenylalanine Derivatives.- 5.4. Oligopeptides Containing Tryptophan and/or Tyrosine.- 6. Radiationless Deactivation of the Excited State.- 7. Phosphorescence of the Aromatic Amino Acids.- 7.1. Temperature Dependence and Solvent Dependence.- 7.2. Tryptophan.- 7.3. Tyrosine.- 7.4. Phenylalanine.- 8. Polarization of Luminescence.- 8.1. Theory.- 8.2. Phenol and Tyrosine.- 8.3. Indole and Tryptophan.- 9. Energy Transfer in Oligopeptides.- 9.1. Radiationless Exchange.- 9.2. Intermolecular Transfer.- 9.3. Intramolecular Transfer in Tyrosine Oligopeptides.- 9.4. Intramolecular Transfer in Oligopeptides Containing Tryptophan and Tyrosine.- 10. Thermoluminescence of the Aromatic Amino Acids.- References.- 6 Luminescence of Polypeptides and Proteins.- 1. Historical Survey.- 1.1. Existence of Excited States.- 1.2. Protein Fluorescence.- 2. Luminescence of Synthetic Polypeptides.- 2.1. Chemistry and Stereochemistry of Polypeptides.- 2.2. Homopolypeptide Luminescence.- 2.3. Heteropolymer Luminescence: Aromatic Amino Acid Systems.- 2.4. Quenching Studies.- 2.5. Photochemistry of Polytyrosine.- 3. Luminescence of Natural Polypeptides: Hormones and Antibiotics.- 3.1. Phenylalanine Systems.- 3.2. Tyrosine-Containing Polypeptides.- 3.3. Tryptophan-Containing Polypeptides.- 3.4. Summary.- 4. Luminescence of Proteins—Class A Proteins.- 4.1. Fluorescence Spectra.- 4.2. Fluorescence Quenching.- 4.3. Phosphorescence.- 4.4. Fluorescence Lifetime.- 4.5. Phosphorescence Lifetime.- 4.6. Temperature-Induced Quenching.- 4.7. Acid Denaturation.- 4.8. Muscle Proteins.- 4.9. Summary.- 5. Luminescence of Proteins—Class B Proteins.- 5.1. Introduction.- 5.2. Tyrosine Fluorescence.- 5.3. Tyrosine Fluorescence and Phosphorescence Spectra.- 5.4. Tyrosine Quantum Yield.- 5.5. Excitation Spectra of Tyrosine.- 5.6. Tyrosine Phosphorescence Yield and Decay Time.- 5.7. Electronic Energy Transfer.- 5.8. Fluorescence Polarization Spectra.- 5.9. Phosphorescence Polarization Studies.- 5.10. Tryptophan Excitation Spectra.- 5.11. Quantum Yields of Tryptophan Residues.- 5.12. Solvent Perturbation.- 5.13. Solvent Isotopic Effect.- 5.14. Temperature Dependence of Quantum Yields.- 5.15. Energy Loss at 77°K.- 5.16. Luminescence Lifetimes.- 5.17. Fluorescence Spectra of Protein Tryptophan Residues.- 5.18. Phosphorescence Spectra of Tryptophan.- 5.19. Stokes’ Shift of Fluorescence.- 5.20. Heterogeneity of Environment.- 5.21. Heterogeneity of Phosphorescence.- 5.22. Transfer and Heterogeneity.- References.