Photochemistry of Macromolecules: Proceedings of a Symposium held at the Pacific Conference on Chemistry and Spectroscopy, Anaheim, California, October 8–9, 1969 PDF
Preview Photochemistry of Macromolecules: Proceedings of a Symposium held at the Pacific Conference on Chemistry and Spectroscopy, Anaheim, California, October 8–9, 1969
PHOTOCHEMISTRY OF MACROMOLECULES PHOTOCHEMISTRY OF MACROMOLECULES Proceedings of a Symposium held at the Pacific Conference on Chemistry and Spectroscopy, Anaheim, California, October 8-9,1969 EDITED BY F. RONALD REINISCH NASA-Ames Research Center Moffett Field, California <J? PLENUM PRESS • NEW YORK-LONDON • 1970 Library of Congress Catalog Card Number 70-127936 ISBN 978-1-4684-8037-5 ISBN 978-1-4684-8035-1 (eBook) DOl 10.1 007/978-1-4684-8035-1 © 1970 Plenum Press, New York· Softcover reprint of the hardcover lst edition 1970 A DiviSion of Plenum Publishing Corporation 227 West 17th Street, New York, N.Y. 10011 United Kingdom edition published by Plenum Press, London A Division of Plenum Publishing Corporation, Ltd. Donington House, 30 Norfolk Street, London W.C.2, England All rights reserved No part of this publication may be reproduced in any form without written permission from the publisher PREFACE Our knowledge of the photodegradation of polymers, chemical evolution, photosynthesis, visual perception and the biological effects of light depends heavily on our ability to elucidate the primary photochemical processes of macromolecules. This volume brings together for the first time from the fields of natural as well as synthetic polymers a group of reports dealing with macromolecular photochemistry. Since macromolecular photo chemistry is an expanding new field that crosses the boundaries between classical disciplines, the reader will encounter the employment of diverse scientific approaches and unfamiliar terminology. However, it has become increasingly apparent that researchers in these fields have much to learn from each other. Although this book is not intended to give a detailed survey of the photochemistry of macromolecules. it does represent the editor's perspective on the relationship between theory, kinetic studies and the synthesis aspects of photochemistry. The ideas expressed by the contributors offer a valuable com posite of theoretical and experimental approaches for those who are concerned with problems which have photochemical relevance, and show that investigators from different fields share many concepts and perhaps some common problems. This novel array of present knowledge should provide a basis for organizing and understanding photochemical information from chemistry, physics, biology and medicine. While of particular value to the research worker, the book also should be of interest to the graduate student about to embark on a problem in macromolecular photo chemistry. It is a privilege to express my deepest appreciation to all those who made the symposium and this book possible. Many of the participants are acknowledged by their papers published in this volume but I am also indebted to Professor Mitchel Shen of the University of California, Berkeley and Professor John Heise of the Georgia Institute of Technology, who gave encouragement and support during the formative stages of this project. Palo Alto, California Ronald F. Reinisch April 17, 1970 v LIST OF CONTRIBUTORS G. M. Androes, Ames Research Center, NASA, Moffett Field, California A. Christopher, General Electric Research & Development Center, Schenectady, New York W. B. Dandliker, Division of Biochemistry, Scripps Clinic & Research Foundation, La Jolla, California E. M. Evleth, Division of Natural Sciences, University of California, Santa Cruz, California A.K. Fritzsche, General Electric Research & Development Center, Schenectady, New York H. R. Gloria, Ames Research Center, NASA, Moffett Field, California J. E. Guillet, Department of Chemistry, University of Toronto, Toronto, Canada A. V. Guzzo, Chemistry Department, University of Wyoming, Laramie Wyoming M. Heskins, Department of Chemistry, University of Toronto, Toronto, Canada H. H. G. Jellinek, Department of Chemistry, Clarkson College of Technology, Potsdam, New York F. Kierszenbaum, Division of Biochemistry, Scripps Clinic & Research Foundation, La Jolla, California J. F. Kryman, Eastman Kodak Company, Rochester, New York viii LIST OF CONTRIBUTORS C. B. Leman, Chemistry Department, University of Wyoming, Laramie, Wyoming S. A. Levison, Division of Biochemistry, Scripps Clinic & Research Foundation, La Jolla, California M. L. MacKnight, Department of Biology, University of Utah, Salt Lake City, Utah A. D. McLaren, College of Agricultural Sciences, University of California, Berkeley, California H. L. Needles, Department of Consumer Sciences, University of California, Davis, California J. Pavlinec, Polymer Institute, Slovak Academy of Science, Bratislava, Czechoslovakia R. Pecora, Department of Chemistry, Stanford University, Stanford, California G. L. Pool, Chemistry Department, University of Wyoming, Laramie, Wyoming R. O. Rahn, Biology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee R. F. Reinisch, Ames Research Center, NASA, Moffett Field, California K. C. Smith, Department of Radiology, Stanford University School of Medicine, Stanford, California J. D. Spikes, Department of Biology, University of Utah, Salt Lake City, Utah M. S. Toy, Douglas Advanced. Research Laboratories, McDonnell Douglas Corporation, Huntington Beach, California M. Weissbluth, Department of Applied Physics, Stanford University, Stanford, California A. N. Wright, General Electric Research & Development Center, Schenectady, New York CONTENTS A Brief History of the Photochemistry of Macromolecules • • 1 A. Douglas McLaren Physical and Environmental Factors Influencing the Photochemistry of DNA • . • . • • • • • • 15 R. O. Rahn The Photochemical Addition of Amino Acids and Proteins to Nucleic Acids 31 K. C. Smith Energy Transfer in Polymeric Ketones in the Solid Phase .• 39 M. Heskins and J. E. Guillet Fluorescence Polarization Kinetic Measurements of Antigen-Antibody Reactions • • • •• 47 S. A. Levison, F. Kierszenbaum, and W. B. Dand1iker The Dye-Sensitized Photooxidation of Biological Macromolecules ••• • • • • • • • • 67 J. D. Spikes and M. L. MacKnight Photolytic Oxidation of Isotactic Polystyrene in Presence of Sulfur Dioxide. Part I - Chain Scission as Function of Temperature at Constant Oxygen and Sulfur Dioxide Pressures and Constant Light Intensity • . • . • • • . 85 H. H. G. Je11inek and J. F. Kryman Photolytic Oxidation of Isotactic Polystyrene in Presence of Sulfur Dioxide. Part II - Photolysis Reaction as Function of Light Intensity, Sulfur Dioxide, and Oxygen Pressures . . • • . • . . . • 91 H. H. G. Je11inek and J. Pav1inec ix x CONTENTS Fluorescence Properties of Visual Pigments . • • • • • •• 105 A. V. Guzzo, G. L. Pool, and C. B. Leman Surface-Photopo1ymerization of Ma1eimides • • • • 117 A. Christopher, A. K. Fritzsche, and A. N. Wright The Effect of Solution Components on Polyacrylamide Gel Formation Via Riboflavin-Sensitized Photopo1ymerization • • • • • • • • • • • 129 H. L. Needles Po1yperf1uorobutadiene. V. Photopo1ymerization of Perf1uorobutadiene •••••••••• 135 M. S. Toy Light Scattering Spectroscopy as a Tool for Studying Macromolecular Dynamics and Chemical Kinetics 145 R. Pecora Hypochromism in Dimers 163 M. Weissb1uth Quantum Mechanically Based Rules for Thermal and Photochemical Reactions • • • • • • • • 167 E. M. Ev1eth Photoe1imination Reactions of Macromolecules •••• 185 R. F. Reinisch, H. R. Gloria, and G. M. Androes A BRIEF HISTORY OF THE PHOTOCHEMISTRY OF MACROK>LECULES A. Douglas MCLaren College of Agricultural Sciences University of California, Berkeley, 94720 INTRODUCTION Ninety years ago Downes and Blunt (1) reported that the activ ity of invertase (zymase) can be destroyed by light and that irra diated solutions can lose residual activity on standing.* The significance of this loss of residual activity was not appreciated until much later (2) (3) (4) when it became clear that some enzyme molecules are unstabilized by ultraviolet radiation, UV; further, some in a population of radiation modified molecules are altered so as to have lost more activity toward one type of substrate than another (5) (6). A differential loss of activity doubtless paral lels selective photochemical events in the molecule (7), for exam ple, when one or more tryptophan residues are modified the proteo lytic activity of trypsin is annililated, but the esterase activity is almost undiminished (8). To-date it is not clear whether some have lost all activity toward one type or the other or molec~les whether molecules can have altered activity toward one type and unaltered activity toward the other. In any case, some molecules are so altered by irradiation as to lose activity almost at once and others to lose activity on standing, or warming, perhaps by * Although a number of biopolymers, including cellulose, wool and rubber, have been irradiated with ultraviolet light, this outline will be confined to molecularly dispersed substances the irradiation of which can have marked biological conse quences, either if irradiated pure in solution, if added, after irradiation, to living cells, or if irradiated within viable cells. These include enzymes, nucleic acids and viruses. Artificial polymers will be discussed by others. 1 2 A. D. MCLAREN rupture of hydrogen bonds or by oxidation and other changes leading simultaneously to absorbance changes (2)0 With malt diatase it was found that the reciprocity law holds (9) and with pancreatin (10) and pepsin (11) first order inactiva tion was observed during irradiation. The reason for these kinetics has since been elucidated in phenomenological terms (12) but a mechanistic explanation is still incomplete. This latter point remains one of the important challenges. The question becomes, what are the photochemical and subsequent chemical changes which lead to enzyme inactivation? From an organic chemical point of view, almost all the expected, possible changes taking place were already observed by 1949, but which changes can be correlated di rectly with enzyme, E, radiation-inactivation still needs to be worked out. PHOTOCHEMISTRY OF ENZYMES Early literature has been summarized (12) and in the past two decades progress has been reviewed (13) (14) (7) (15). At one time it was suggested that inactivation studies as a function of wave length might reveal curves similar in shape to those for model sub stances and thereby give some clue as to the chemical groupings about the active site (16). Eventually this was done with dry trypsin by Setlow and Doyle (17). They resolved their action spec trum into two components, one representing photons absorbed by cystine residues, the other representing photons absorbed by the remainder of the molecule. At 2537K cystine residues are of para mount importance., but aromatic residues are more important at ca. 2850K and even peptide bonds become important at short wavelengths. If irradiation can lead to inactivation by more than one chemical mechanism, then the total rate of inactivation will be given by (provided there is no energy transfer among residues): 1) where [E] is the concentration of enzyme, with an initial concen tration [Eo] and an extinction coefficient £E' ni is the number of chromophores of kind i in the molecule, having residue extinction coefficient £i and undergoing photochemical reaction for modifica tion with a quantum yield The kinds of amino acid residues of ~i' photochemical significance in the enzyme include aromatic groups, and cystine if present. If n is two or more and a given kind of i residue, for example, cystine, has a different ~i and £i for each position in a molecule, then nij residues with specific £ij and ~ij
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