Photochemistry of Proteins and Nucleic Acids

Contents

Preface

I. Some Principles of Photochemistry

A. Introduction

1. The Laws of Photochemistry

2. Absorption Spectroscopy

3. Transfer Mechanisms of Excitation Energy

B. Factors of Influence in Photochemical Reactions in Solution

1. The Absorption of Light and the Quantum Yield

2. General Nature of Photochemical Reactions in Solution

II . Absorption and Luminescence Spectra of Nucleoproteins and their Components

A. Proteins

1. Principal Absorbing Groups in Proteins

2. Free and Bound Phenolic Hydroxyl Groups in Proteins

3. Pep Tide Absorption in the Range 2400-3200Å

4. Absorption By Fibrous Proteins

5. Apparent Absorption of Light Attributable to Scattering

6. Extraneous Absorption in Proteins

7. Peptide Absorption Below 2400Å

8. Excited States of Proteins

B. Nucleic Acids

1. Purines and Pyrimidines

2. Nucleosides and Nucleotides

3. Nucleic Acids, Polynucleotides and Oligonucleotides

C. Nucleoproteins

D. Viruses

III . Action of Ultraviolet Light on Amino-Acids, Peptides and Related Substances

A. Direct Action

1. Photochemistry of the End Groups

2. Photochemistry of the Peptide Bond

3. Photochemistry of Side Groups and of Amino-Acids

B. Photosensitized Destruction of Amino-Acids in the Presence of Dyes

IV . Action of Ultraviolet Light on Proteins : General

1. Site of Action of Ultraviolet Light On Proteins

2. Changes in The Absorption Spectra of Proteins with Irradiation

3. Photolysis and Aggregation of Irradiated Proteins

(A) Photolysis of the Peptide Bond

(B) Effect of Ultraviolet Light On Disulfide Linkages

(C) Aggregation Phenomena

4. Irradiation of Protein Monolayers

V. Photochemical and Photosensitized Inactivation of Enzymes

1. Kinetics of Enzyme Inactivation in Solution

2. Mechanism of Inactivation of Enzymes By Ultraviolet Light

3. Kinetics of Inactivation of Dry Enzymes

4. Photosensitized Inactivation of Enzymes

VI. Photochemistry of Purine and Pyrimidine Derivatives

1. Carbohydrates

2. Purine Derivatives

3. Purine Nucleotides

4. Nucleotide Co-Enzymes

5. Pyrimidine Derivatives

6. Reversible Photoproducts of Uracil Derivatives

7. Photochemically Induced Additions to Double Bonds

8. Dimer Photoproducts

9. Kinetics and Mechanism of Photochemical Transformation of Some Uracil Analogues

10. Reversible Photoproducts of Cytosine Derivatives

(A) Nature of Photoproducts of Cytosine Glycosides

(B) Cytosine and l-Methylcytosine

(E) Quantum Yields For Cytosine Derivatives

(D) Kinetics of Reverse Reaction

11. Primary Photoproducts of Substituted Pyrimidine Derivatives

12. Photodegradation Products of Pyrimidine Derivatives

VII. Nucleic Acids and Oligo - and Polynucleotides

A. General

B. Photochemical Degradation of Nucleic Acids

1. Deoxyribonucleic Acids

2. Nucleic Acid Films

3. Ribonucleic Acids

C. Nucleoproteins

D. Biological Inactivation

1. Infectious RNA

2. Transforming Deoxyriboneucleic Acids (T-DNA)

3. RNA Core

E. Kinetics of Biological Inactivation of Nucleic Acids

F. Reversibility of Nucleic Acid Photolysis

1. Physico-Chemical Evidence For Reversibility

2. Reversal of Biological Inactivation

G. Summary of Primary Effects of Ultraviolet Light On Nucleic Acids

H. Indirect Irradiation Effects

VIII. Inactivation of Virus

A. Introduction

B. Inactivation Studies with A Plant Virus

C. Photochemically Produced Vaccines

D. Bacteriophages

1. DNA Content and UV Lethality

2. Action Spectra

3. Quantum Yields

4. Kinetics of Inactivation of Infectivity

5. Phage-Host Interactions

E. Photosenisitized Inactivation

IX. Some Selected Problems in Photobiology

A. Radiation Receptors in Biological Systems : Action Spectra

1. Wavelength Dependence of Quantum Yields

2. Examples of Action Spectra Studies

3. Partial Cell Irradiation

B. Reversal of Initial Photobiological Effects : Photoreactivation

1. Ultimate Effects of Ultraviolet Irradiation

2. Characteristics of Photoreactivation

3. Radiation Receptors in Photoreactivation

4. Physical Models As Analogies of Photoreactivation

5. Alternative Methods For Reversal of Ultraviolet Effects

6. Potential Reversible Photochemical Transformations In Nucleic Acids

C. Radiation Induced Syntheses : Origin of Life

Appendix. Some Techniques in Photochemistry

A. Light Sources

1. Mercury Arcs

2. Carbon Arcs

3. Xenon Arcs

4. Low-Pressure Mercury Resonance Lamps

5. 1849 Å Resonance Lamp

6. Simple Laboratory Sources of 2537 À Radiation For Inactivation Studies and Preparative Photochemistry

7. Monochromators

8. Flash Discharge Sources

B. Flash-Photolysis Flash-Spectroscopy

C. Spectral Filters

1. Solid Filters

2. Chemical Filter Combinations

D. Measurement of Light Intensity

1. Physical Methods

2. Chemical Actinometry

E. Microbeam, Or Partial Cell, Irradiation

Bibliography

Index