PHOTOBIOLOGY The Science and Its Applications

Edited by Emanuel Riklis Israel Atomic Energy Commission Beer-Sheva, Israel

PLENUM PRESS • NEW YORK AND LONDON

Library of Congress Cataloging-1n-Pub11catIon Data

I n t e r n a t i o n a l Congress on P h o t o b i o l o g y MOth 1988

P h o t o b i o l o g y : the s c i e n c e and i t s a p p l i c a t i o n s

Emanue 1 R I k 1 I s .

J e r u s a 1 em )

e d i t e d by

o . cm.

"Pr o c e e d i n g s of the Tenth I n t e r n a t i o n a l Congress on P h o t o b i o l o g y .

h e l d October 30-Ncvember 6, 1988, in J e r u s a l e m , I s r a e l " - - T . p . v e r s o .

I n c l u d e s b l b l i o g r a p h i c a l r e f e r e n c e s and i n d e x e s .

ISBN 0-306-43830-5

1. P h o t o b i o l o g y — C o n g r e s s e s . I. R i k l i s , Emanue 1. I I . T i t l e .

[DNLM: 1. B i o l o g y - - c o n g r e s s e s . 2. L i g h t — c o n g r e s s e s .

3. Photochem 1 s t r y - - c o n g r e s s e s . 4. U l t r a v i o l e t R a ys--congresses .

QH 515 I61p 1988]

QH515.I57 1988

574.I9'153--dc20

DNLM/DLC

f o r L i b r a r y of Congress 91-3013

Proceedings of the Tenth International Congress on Photobiology, held October 30-November 6, 1988, in Jerusalem, Israel

ISBN 0-306-43830-5 Cover Illustration: Figure 4a from article in European Journal of Cell Biology, Vol. 46, 2 27 - 2 32 (1988). © 1991 Plenum Press, New York A Division of Plenum Publishing Corporation 233 Spring Street, New York, N.Y. 10013 All rights reserved No part of this book may be reproduced, stored in a retrieval System, or transmitted in any form or by any means, electronic, mechanical, photocopying, microfilming, recording, or otherwise, without written permission from the Publisher Printed in the United States of America

CIP

Contents

Opening of the Congress R. L a t a r j e t , H o n o r a r y P r e s i d e n t 1

AIP Presidential Lecture: Themes and Trends in Photobiology K . K . R o h a t g i - M u k h e r j e e 3

A Half Century of Photobiology: The Alexander Hollaender Memorial Symposium Alexander Hollaender (1898-1986)

R. L a t a r j e t 15 Alexander Hollaender: The Man and His Work

R . B . Setlow 17 Defective D N A Repair and Human Disease

A . R. L e h m a n n 21 DNA-Protein Crosslinking in UV-Irradiated Human and ICR 2A Cell Lines

B . S. Rosenstein a n d L i - W e n L a i 27 Retroviral Based Shuttle Vectors and Endogenous Cellular Genes: Complementary

Approaches for Investigations of Mutational Specificity E . A . D r o b e t s k y , AJ. G r o s o v s k y , A . S k a n d a l i s , L . R. Shekter

a n d B . W. G l i c k m a n 35

Ultraviolet and Ionizing Radiations: From Molecules to Cells Photobiology and Radiobiology: Divisions and Common Ground

/ . Z. Beer 43 Comparative Effects of Ultraviolet and Ionizing Radiations on Nucleic Acids

/. Cadet, M . B e r g e r , P . C. J o s h i , A . Shaw, L . V o i t u r i e z , L . - S i n g K a n a n d R. W a g n e r 49

Interaction Between Ultraviolet and Ionizing Radiation in Eukaryotic Cells /. K i e f e r 61

xi

A Molecular Model for the Cytotoxic Action of U V and Ionizing Radiation H . P . Leenhouts a n d K H . C h a d w i c k 71

Mutagenic Effects of Ultraviolet and Ionizing Radiation H . H . Evans 83

Malignant Transformation by Ultraviolet and Ionizing Radiations J . B . L i n i e 97

Between Ultraviolet and Ionizing Radiation: Action Spectra for Cytotoxicity in the Vacuum-UV Region T. ho 105

UV Light and DNA Damage, Repair and Mutagenesis Brief Methodological Survey of the Photochemistry of Nucleic Acid Constituents and

Analogues, and Some Biological Applications, Including Photo-Affinity Labeling D . Shugar, B . K i e r d a s z u k a n d R. S t o l a r s k i 115

The Sequence Specificity of Ultraviolet Light Damage to D N A Containing Bromodeoxyuridine or Iododeoxyuridine V. M u r r a y a n d R. F . M a r t i n 135

UV-Light Induced Perturbation of D N A Tertiary Structure: Consequences on the Enzymes Controlling Chromosome Superhelicity A . M . P e d r i n i , F . S p i r i t o , a n d S. T o r n a l e t t i 141

Excision-Repair Capacity in U V Irradiated Strains of S. p n e u m o n i a e A . M . Estevenon a n d N . S i c a r d 149

UV-Inducible Repair in Yeast F . E c k a r d t - S c h u p p , A . A h n e , S. O b e r m a i e r a n d S. Wendel 155

Mutant 112X86 Versus Wild-Type L a c Repressor Photochemistry M . S p o t h e i m - M a u r i z o t , F . C u l a r d , P . G r e b e r t , J . - C . M a u r i z o t a n d M . C h a r l i e r 163

umuC-Independent, recA-Dependent Mutagenesis K . C. S m i t h a n d N . J . S a r g e n t i n i 169

What Is The Molecular Mechanism Of U V Mutagenesis in E s c h e r i c h i a c o l i ! J . R. B a t t i s t a , T. N o h m i , C. E . D o n n e l l y , a n d G. C . W a l k e r 177

Ultraviolet Mutagenesis of a Shuttle Vector Plasmid in Repair Proficient and Deficient Human Cells M . M . Seidman, D . B r a s h , S. S e t t h a r a m , K . H . K r a e m e r a n d A . B r e d b e r g 183

Mutational Hotspots in Mammalian Cells C h a r l e s R. Ashman 193

Spectra of Mutations Induced by Structurally-Related Aromatic Polycyclic Carcinogens during Replication of a Shuttle Vector in Human Cells V. M . Mäher, J - L . Yang, M . C - M . M a h , a n d J . J . M c C o r m i c k 199

Twenty Years of Research on Xeroderma Pigmentosum at the National Institutes of Health K . H . K r a e m e r 211

xii

The Edna Roe Memorial Lecture Repair Control of Photoinduced Cross-Links and Monoadducts in D N A :

Genetic, Molecular and Evolulionary Features E . M o u s t a c c h i 223

Photochemistry and Photophysics: Probing the Unknown Pulse Radiolysis and Flash Photolysis

T.G. T r u s c o t t 237 Discrimination and Coverage in Hybridization: Advantages Afforded by Crosslinkable

Oligonucleotide Probes G. D . C i m i n o , H . B . G a m p e r , M . F e r g u s o n , S. T. Isaacs a n d J . E . H e a r s t 249

The Analytical Uses of Luminescence G. G a b o r 267

Electric Parameters of Purple Membrane Fragments S.G. T a n e v a a n d L B . P e t k a n c h i n 277

Probing the Internal Spectral Distribution of U V Radiation in Plants with Fibre Optics J . F . B o r n m a n a n d T.C. V o g e l m a n n 287

Cancer Diagnosis by Fluorescence Polarization A . W e i n r e b , M . D e u t s c h a n d S. C h a i t c h i k 293

Microspectrofluorometry of Human Melanoma Cells and Fibroblasts Treated with Azelaic Acid E . K o h e n , C. K o h e n , D . O . Schachtschabel, J . G . H i r s c h b e r g , B . L . S h a p i r o a n d A . M c h e i l e h 305

Recent Advances in Chemical Modeling of Bacterial Bioluminescence Mechanism S.-C. T u a n d H I . X . M a g e r 319

Use of Image Analysis in Photobiology D - P . H a d e r 329

Degradation of Oligonucleotides and D N A by V U V Radiation in Solids T . I t o 345

Photolysis of Water by V U V Radiation and Reactions with D N A and Related Compounds in Aqueous Systems M . K u w a b a r a , A . M i n e g i s h i , K . T a k a k u r a , K . H i e d a a n d T. I t o 355

Light Regulated Biological Processes — Photosynthesis Trapping of Excitation Energy in Photosynthetic Purple Bacteria

R. v a n G r o n d e l l e , H . Bergström a n d V. Sundström 367 The Supramolecular Structure of the Light-Harvesting System of Cyanobacteria and Red

Algae E . Mörschel, G . - H . Schatz, W. L a n g e 379

Quinone Substituted Porphyrin Dimers: New Photosynthetic Model Systems J . L . Sessler,M.R. J o h n s o n , S.E. C r e a g e r J . F e t t i n g e r , J A . I b e r s , J . R o d r i g u e z , C. K i r m a i e r , a n d D . H o l t e n 391

xiii

Organization of the Photosynthetic Membrane of Rhodopseudomonas V i r i d i s Using Biochemical, Immunological and Electron Microscopical Methods F . A . J a y 401

Photoreceptors: Phytochrome The Chromophore and its Role in the Phototransformation of Phytochrome

Conformational Changes Probed with bis-ANS, Monoclonal Antibodies and Phosphorylation P.S. Song, U. B a i , I . - S . K i m , G. C. W h i t e l a m a n d J . P . M a r k w e l l 411

Molecular Properties of Phytochrome W. Rüdiger 423

Studies of the Mechanism of the Phototransformation of Phytochrome C. B o n a z z o l a , G. V a l d u g a , P . L i n d e m a n n , Y. Käß, S.E. B r a s l a v s k y a n d K . S c h a f f n e r 435

The Significance of Mutants in Phytochrome Research R.E. K e n d r i c k , P . Adamse, E . Löpez-Juez, M . K o o r n n e e f , J . L . Peters a n d J . C . Wesselius 437

Mode of Coaction between Phytochrome and B lue/UV Photoreceptors H . M o h r a n d H . D r u m m - H e r r e l 445

Phytochrome Regulated Expression of Cab Genes in Higher Plants F . N a g y , E . F e j e s , A . Pay a n d E . A d a m 455

Phytochrome Structure/Function Relationships as Probed by Monoclonal Antibodies L . H . P r a t t , M . - M . C o r d o n n i e r a n d L . C r o s s l a n d 461

Phytochrome from Green A v e n a Characterized with Monoclonal Antibodies Directed to It M . - M . C o r d o n n i e r a n d L . H . P r a t t 469

Phytochrome and Cryptochrome: Coaction or Interaction in the Control of Chloroplast Orientation W. H a u p t 479

Photochemistry and Photophysics of Biliprotein Chromophores: A Case of Molecular Ecology

H . Scheer 491 Strategy of Orientation in Flagellates

D . P . H a d e r 497 Polarized Spectra of Immobilized Phycobilisomes Isolated from Various Cyanobacteria

D . F r a c k o w i a k , Y. F u j i t a , L . G . E r o k h i n a , M . M i m u r o , Y. Yamazaki, N . T a m a i , M . N i e d b a l s k a , M . R o m a n o w s k i a n d J . S z u r k o w s k i 511

Rhodopsins Spectra and Structures of Photorhodopsin and Bathorhodopsin Studied by Picosecond Laser Photolysis

T. Y o s h i z a w a , Y. S h i c h i d a a n d H . K a n d o r i 521

xiv

The Primary Photochemical Process in Bacteriorhodopsin W. Z i n t h a n d D . O e s t e r h e l t 531

Functional Domains in Octopus Rhodopsin M . T s u d a , T. T s u d a , N . G . A b d u l a e v , a n d S. M i t a k u 537

Picosecond Time-resolved Spectroscopy of the Initial Events in the Bacteriorhodopsin Photocycle G e o r g e H . A t k i n s o n 547

Primary Processes in Sensory Rhodopsin and Retinochrome T. K o b a y a s h i , H . O h t a n i , M . T s u d a , K . O g a s a w a r a , S. K o s h i h a r a , K . I c h i m u r a , R. H a r a , a n d M . T e r a u c h i 561

Circadian Rhythms Seasonal Changes in Circadian Rhythm of Thermoregulation in Greenfinches and

Siskins at Different Ambient Temperatures S. S a a r e l a , B . K l a p p e r a n d G. H e l d m a i e r 573

Light and Circadian Activity in the Blind Mole Rat R. R a d o , H . Gev, B . D . G o l d m a n , a n d J . T e r k e l 581

Photoperiod Changes and Heat Production in M e r i o n e s Crassus — The Role of Circadian Rhythms of Body Temperature in Seasonal Acclimatization

A . H a i m , a n d G. L e v i 591 Physiological Responses of Melatonin-Implanted Pigeons to Changes in Ambient

Temperature T M . J o h n a n d J . C . G e o r g e 597

Metatonin Binding Sites in Discrete Brain Areas: Coincidence with Physiological Responsiveness N . Z i s a p e l 607

Solar UV Light Effects on Growth and Development Signal Transduction in Blue Light-Mediated Growth Responses

T. W. S h o r t , M . L a s k o w s k i , S. G a l l a g h e r , a n d W. R. B r i g g s 615 Potential Impacts of Increased Solar U V - B on Global Plant Productivity

A M . T e r a m u r a a n d J . H . S u l l i v a n 625 Effects of Enhanced Solar U V - B Radiation on Growth and Function of Selected Crop

Plant Seedlings M . T e v i n i , U. M a r k , G. F i e s e r a n d M . S a l l e 635

Man and Ultraviolet Light — Photosensitization and Photocarginogenesis Sources of Human Exposure to Ultraviolet Radiation

B . L . Diffey 653 Drug Products and Photocarcinogenesis

P I > . F o r b e s , R.E. D a v i e s a n d C.P. Sambuco 663

xv

Investigating Contact Photoallergy in the Mouse G.F. G e r b e r i c k a n d C A . Ryan 671

Relation Between the Molecular Structure of a Drug and its Photobiological Activity by Combination of I n v i v o and I n v i t r o Research

G . M . J . B e i j e r s b e r g e n v a n H e n e g o u w e n 683 Screening Materials for Photosensitization Eye Effects

P . D a y h a w - B a r k e r , P h . D . a n d F . M . B a r k e r , O D 693

UV and Cancer Solar Ultraviolet Radiation and Skin Cancer in Man

F . U r b a c h 705 The Finsen Medal Presentations:

to: D.I. Arnon L.O.Björn 715

to: I.A. Magnus AJR. Y o u n g 717

The Finsen Lecture: M o n o d e l p h i s d o m e s t i c a : An Animal Model for Studies in

Photodermatology Including the Induction of Melanoma R. D . Ley 719

Prolonged UVR-Induced Erythema and Melanoma Risk Factors E . A z i z i M . D . , Y. Wax P h . D . , A . Lusky M . S c , A . Kushelevsky P h . D . , a n d M . S c h e w a c h - M i l l e t M . D 723

Ultraviolet Radiation Induces Cytoskeletal Damage in Human Cells G. B . Zamansky a n d I . - N . C h o u 727

Photoimmunology Overview: Photoimmunology

M L . K r i p k e 735 Immunology of UV-Induced Human Skin Cancer

G. F r e n t z 743 Immunological Mediators Produced by UV-Irradiated Keratinocytes

T. S c h w a r z , A . U r b a n s k i , J . K r u t m a n n , T A . L u g e r 749

The Franz Greiter Memorial Symposium: Physiological Effects of UV Radiation on the Immune System and on the Eye Franz Greiter — The Man and His Work

F . U r b a c h 761 Immune Suppression by Ultraviolet B Irradiation and Urocanic Acid

F . P . N o o n a n a n d E . C . D e F a b o 763

xvi

Effects of Radiant Energy on the Ocular Tissues S. Z i g m a n , P h . D 769

On the Effect of Ultraviolet Radiation on the Eye 0. H o c k w i n , J . Schmidt, a n d C. S c h m i t t 787

Photodynamic Therapy Model System Studies on Photosensitization in Light Scattering Media

L . I . G r o s s w e i n e r , M J . S c h i f a n o , J . L . K a r a g i a n n e s . Z. Z h a n g a n d Q . A . E l a n 795 I n V i t r o a n d I n V i v o Spectral Properties of Porphyrins

R. P o t t i e r 807 Photosensitization of Microbial Cells

Y. N i t z a n , Z. M a l i k , a n d B . E h r e n b e r g 815 Effects of PDT on D N A and Chromosomes

J . M o a n , E . K v a m , E . H o v i g a n d K . B e r g 821 Photophysical and Photosensitizing Properties of Phthalocyanines

J . D . Spikes 831 Zinc(II)-Phthalocyanine as a Second-Generation Photosensitizing Agent in

Tumour Phototherapy G. J o r i , R. B i o l o , C. M i l a n e s i , E . Reddi a n d G. V a l d u g a 839

Photosensitization by Phthalocyanines. Chemical Structure — Photodynamic Activity Relationship

/. R o s e n t h a l a n d E . B e n - H u r 847

Photoprotection A. Cellular Mechanisms

Cellular Effects of U V A : D N A Damages M J . Peak a n d J . G . Peak 855

Cellular Defense Against U V A (320-380 nm) and U V B (290-320 nm) Radiations R . M . T y r r e l l , SM. Keyse a n d E . C . M o r a e s 861

Melanin is a Double-Edged Sword J . M . M e n t e r , I . W i l l i s , M . E . T o w n s e l , G. D . W i l l i a m s o n a n d C. L . M o o r e 873

B. Protection Measures Sun Protection Factors

R.E. M a s c o t t o 889 The Reliability of Sun Protection Factor

E . A z i z i M . D . , M . M o d a n , A . Kushelevsky P h . D . a n d M . Schewach M i l l e t M . D 897

Sunscreens — A Photochemical Perspective F . P . G a s p a r r o 9 0 1

The Protective Ability of Sunscreens G. A . G r o v e s 9 ^3

The Broad Spectrum Concept in Sunscreens G . A . G r o v e s 909

Trends in Sun Protection R.S. Summers a n d B . Summers 917

Psoralens: Effects and Mechanisms Photochemoprotection: Protective Effects of Psoralen-Induced Tan

P . F o r l o t 925 Mutagenic Effects of Psoralen-Induced Photoadducts and their Repair in Eukaryotic Cells

D . A v e r b e c k . M . D a r d a l h o n a n d N . M a g a n a - S c h w e n c k e 933 Quantification of 8-MOP Photoadducts in Lymphocytes

F . P . G a s p a r r o , D . W e i n g o l d , E . Simmons, D . G o l d m i n z , R. E d e l s o n 951 New Aspects of the Mechanism of Action of Furocoumarins (Psoralens and Angeiicins)

G. R o d i g h i e r o 963 Photodynamic Carcinogenicity and its Prevention by Carotenoids as Oxygen Radical

Quenchers: Relevance in Animals and Human Intervention L . S a n t a m a r i a 975

UV and the Environment U V and the Environment: An Introduction

E . R i k l i s 1011 U V and Exobiology: Can Micro-Organisms Survive the Space Environment?

H . - D . M e n n i g m a n n 1015 Further Solar U V Spectral Measurements at the Dead Sea

A . P . Kushelevsky 1023 Ozone and Ultraviolet Light are Additive Co-Carcinogens I n V i t r o

C. B o r e k 1027

UV Risks and Regulations Skin Photobiology and Regulations on U V Radiation

J . C. v a n der L e u n 1033 Patterns of Human Exposure to Ultraviolet Radiation

F r e d e r i c k U r b a c h 1037 Cutaneous Photosensitization: Hazard and Regulation

B . E . J o h n s o n 1045 U V Regulatory Strategies

S.M. Sykes a n d E . D . Jacobson 1057

Round Table: Photobiology in Developing Countries 1069 Author Index 1073 Subject Index 1077

xviii

Photochemistry and Photophysics of Biliprotein Chromophores: A Case of Molecular Ecology

H U G O SCHEER Botanisches I n s t i t u t der Universitaet M e n z i n g e r Str. 6 7 D - 8 0 0 0 M u e n c h e n , FRG

Biliproteins are widespread pigments in nature, and perform a variety of rather different functions (Kayser, 1985; Scheer, 1982; Braslavsky et al., 1983; Ruediger and Scheer, 1983): The phycobiliproteins occurring in cyanobacteria, rhodophytes and cryptophytes, function as photosynthetic light-harvesting pigments. Photochromes are sensory photoreceptors in plants and algae, and the putative adaptochromes and photomorphochromes of cyanobacteria are probably also biliproteins. The bilirubin-serum albumin conjugates are involved in transporting this poorly water-soluble pigment, and many invertebrates contain biliproteins which play a role in their pigmentation, but may have additional functions.

According to these different functions, the photochemical and photophysical properties of these complexes are rather diverse; a fact that is surprising in view of the structural similarities of many of the chromophores involved. The relative contributions of different deexcitation pathways are regulated by specific interactions between the chromophores and the proteins. In analogy to interactions among living Systems, I like to term these interactions as "molecular ecology".

In the context of studies on phycobiliproteins from cyanobacteria, we became interested in the factors regulating the contributions of the different deexcitation pathways, as well as in the influence of chromophore structure and photochemistry on protein structure and aggregation. Additional reasons for such studies are the potential buildup of background during time-resolved and other laser-spectroscopic techniques working at high intensities or repetition rates, and the possible involvement of phycobiliproteins in light perception (Bjoern and Bjoern, 1980; Scheer, 1982; Kufer, 1988).

Today, I would like to report some recent work we have done with two phycobiliproteins, phycocyanin and phycoerythrocyanin from the thermophilic cyanobacterium, M a s t i g o c l a d u s l a m i n o s u s , for which primary (Zuber, 1986) and crystal structures (Schirmer et al., 1987; Duerring and Huber, private communication, 1988) are known.

P h o t o b i o l o g y , Edited by E . Riklis Plenum Press, New York, 1991 491

H u g o Scheer Phycocyanin Molecular Ecology

Energy transfer

Experimental work on this subjcct has been carried out in Cooperation with Siegfried Schneider (Technical University, Muenchen, F R G ; Schneider et al., 1988). Both pigments in different aggregate sizes, and their a- and ß-subunits have been studied by two complementary picosecond techniques: The decay of fluorescence and of fluorescence polarization was measured with a repetitive streak-camera, and the ground-state de- and repopulation kinetics by absorption-recovery.

The smallest PC-unit, e.g. the monomer of the ot-subunit, shows >95% of Us fluorescence as a single-exponential decay with a rate constant of appx. 900 psec, an expected pattern for a Single, isolated chromophore. More complex decay patterns had been observed before in subunit preparations which we now know were dimers. However, aggregation does not change the decay pattern and the depolarisation, and energy transfer among the two chromophores in the ot2-dimer appears to be negligible. The ß-subunit shows a biexponential decay, with rate constants in the 30 and 1100 psec ränge. The first is due to energy transfer from the high-energy ß-155 to the low-energy ß-84, because Population of the excited State of ß-84 is delayed relative to the excitation of ß-155 by this time. A l l higher aggregates require threc or even more exponential components to fit the decay patterns. The most dramatic change occurs upon aggregation of the (otß)i monomers (=heterodimers) to the (aß)3 trimers (= heterohexamers), where depolarization kinetics are increased by an order of magnitade.

In Cooperation with Ken Sauer (University of California, Berkeley), we have simulated the dynamics by using several models for energy transfer, and the chromophore geometries as determined by x-ray crystallography (Sauer and Scheer, 1988). Although a model based on Foerster-type energy transfer gives results which model satisfactorily existing experimental data, there is evidence that excitonic coupling cannot be ignored in trimers and higher aggregates. a-84 on one monomeric unit, and ß-84 on the adjacent one, come so close that Foerster transfer times <1 psec are calculated, and excitonic coupling energies in the ränge of 7 5 c m - 1 . This intermediatc region between Foerster transfer and excitonic interaction is hitherto only little explored, and the phycobiliproteins may be useful in this respect.

Radiationless deactivation

The single-exponential lifetime of the a-subunit is in the ränge of 900 psec, whercas the longest fluorescence component in larger aggregates (assigned to cumulative decay of all chromophores over which excitation energy is thermally equilibrated) is 1.4-2 nsec. Since oscillator strengths of the chromophores do not change markedly upon aggregation of the phycobiliproteins, the increase in fluorescence lifetimes then corresponds to a decrease in energy losses with increasing aggregate size. This corroborates earlier steady-state results showing an increase in fluorescence yields from around 40% in subunits to close to 90% in aggregates.

As photochemistry to stable produets is no major deexcitation pathway in PC see

492

P^ycocyanin Molecular Ecology H u g o Scheer

below), and intersystem crossing is not important eithcr, these losses are due to efficient imternal conversion. Three mechanisms to this have been discussed in free bile pigments (Scheer, 1982, Braslavsky et al., 1983). The first is a high density of vibrational states, which is related to the high conformational flexibility of bile pigments. The second d<eexcitation mechanism is v i a photochemical Channels leading to the ground-state of u.nstable products, which revert to the ground State of the original species. Specifically, internal H-transfer and Z/E-isomerizations at the central methine bridge (C-10/11) have been discussed. Isomerization involves rather large structural changes which are unlikely in the native or near-to-native protein environment. H-transfer is, on the other hand, even a candidate for photochemistry at temperatures close to absolute zero (Koehler et al., 1988). Little is known on the flexibility of the chromophores in their native environment, but reagents known to increase protein mobility decrease biliprotein fluorescence. Obviously, the details of radiationless deexcitation need further study.

Photochemistry

Whereas the photochemical events discussed in the context of radiationless decay are transitory, long-lived photoproducts have been observed in several phycobiliproteins. The most interesting and potentially most important type of photochemistry is observed upon partial denaturation. This photochemistry has now been found to occur under a variety of conditions. Its magnitude (defined by the ratio of the amplitude of the difference spectrum, to the maximum absorption) can be as high as 60% in the presence of 20% mercaptoethanol. It is most likely due to a Z/E interconversion of the chromophore(s) at the C-15,16 double-bond. Under such conditions, the chromophores are apparently capable to perform the same type of photochemistry as that of phytochrome.

More recently, we have studied in Cooperation with W. Kufer from our laboratory a different pigment, e.g. PEC. Its ot-subunit had been linked previously to photochromic activities in eyanobaetcrial extracts, and possibly to photomorphogenesis (Bjoern and Bjoern, 1980; Kufer, 1988). This pigment, which is structurally very similar to PC (Bryant, 1982; Duerring and Huber, private comm.), carrries a rare phycoviolobilin chromophore at cys ot-84 (Bishop et al., 1987), which replaces the common phycocyanobilin chromophore present at the same location in PC. Being a component of the phycobilisome, it is commonly regarded a light-harvesting pigment. A distinet difference from other phycobiliproteins, is however its pronounced photochemistry in the native State, which is most likely again a Z/E-isomerization at the C-15 methine bridge. Th reaction would require a decreased rigidity in the environment of ot-84, which has been born out in the crystal structure of PEC (Duerring and Huber, private comm.).

Effect of chromophore a-84 on aggregation

Recently, we noticed that PEC shows not only increased photochemistry upon disaggregation, but there is also a reeiprocal dependence of biliprotein aggregation on photochemistry. When PEC is alternately irradiated with orange (600nm) and green light

493

H u g o Scheer Phycocyanin Molecular Ecology

(500nm), the two photoequilibria were enriched in the 15-E- and 15-Z-configured forms, of a-84 chromophore respectively. Ultracentrifugation showed, that at the same time there occurs a photoreversible change in aggregation: The amount of trimer increased each time the last irradiation was with green light, and decreased each time it was with orange light. This means, that the configuration of a-84 controls aggregation. This can be rationalized again from the X-ray structure: a-84 is located very close to the contact surface of monomers in trimers.

To test the sensitivity of aggregation to the structure of a-84 we have done another experiment with PC. The chromophores in isolated subunits were reduced to rubins. Modified a-subunits were then hybridized with original ß-subunits and v i c e v e r s a to yield hybrid PC. In this experiment, the hybrids containing modified a-subunit only formed monomers, whereas those hybrids containing modified ß-subunits reaggregated to trimers.

This result points to an involvement of the biliprotein chromophores not only in energy transfer and photochemistry of biliproteins, but also in their structure. This effect may well be at the origin of a Signal chain leading eventually to photomorphogenesis. In a more general context, it is an example for the intricate interplay of proteins with their cofactors, which leads to the stunning variety of properties of pigments with the same or very similar molecular structures.

References

Bishop, J.E., Rapoport, H., Klotz, A.V., Chan, C.F., Glazer, A.N., Fueglistaller, P., and Zuber, H., 1987, Chromopeptides from phycoerythrocyanin. Structure and linkage of the three bilin groups, Journal of the American Chemical Society 109:875-881.

Bjoern, L.O., and Bjoern, G.S., 1980, Photochromic Pigments and photoregulation in blue-green algae, . Photochemistry and Photobiology 32:849-852.

Braslavsky, S., Holzwarth, A.R., and Schaffner, K.,1983, Solution conformations, photophysics and photochemistry of bilipigments. Bilirubin- and biliverdindimethyl-esters and related linear tetrapyrroles, Angewandte Chemie 94:670-689. International Edition (English) 22:656-674.

Bryant., D., 1982, Phycoerythrocyanin and phycoerythrin: Properties and occurence in cyanobacteria, Journal of General Microbiology 128:835-844.

Kayser,H., 1985, in Comprehensive Insect Physiology, Biochemistry and Pharmacology edited by G.A. Kerkut and L.I. Gilbert, (New York: Pergamon), pp. 367-415.

Koehler, W., Friedrich, J., Fischer, R., and Scheer, H., 1988, Low temperature spectroscopy of cyanobacterial antenna pigments, in Photosynthetic Light-Harvesting Systems: Organisation and Function edited by H.Scheer and S.Schneider, (Berlin: W. deGruyter), pp. 293-306.

Kufer, W., 1988, Concerning the relationship of light-harvesting biliproteins to phycochromes in cyanobacteria, in .us on;Photosynthetic Light-Harvesting Systems: Organisation and Function edited by H.Scheer and S.Schneider, (Berlin: W. deGruyter), pp. 89-92.

Ruediger, W., and Scheer, H., 1983, Chromophores in Photomorphogenesis, in Encyclopedia of plant physiology, Vol. 16, Photomorphogenesis edited by W. Shropshire and H. Mohr (Berlin: Springer), pp. 119-151.

Sauer, K., and Scheer, H., 1988, Excitation transfer in C-phycocyanin: Foerster transfer rate

494

Prnycocyanin Molecular Ecology H u g o Scheer

and exciton calculations based on new crystal structure data for C-phycocyanins from Agmenellum quadruplicatum and Mastigocladus laminosus, Biochimica et Biophysica Acta 936:157-170.

Sc:heer, H., 1982, Phycobiliproteins: Molecular aspects of photosynthetic antenna System, in Light reaction path of photosynthesis edited by F.K. Fong (Berlin: Springer), pp. 7-45.

Scihirmer, T., Bode, W., Huber, R., 1987, Refined 3-dimensional structures of 2 cyanobacterial C-phycocyanins at 2.1 and 2.5A resolution - A common principle of phycobilin-protein interaction, Journal of Molecular Biology 196:677-695.

Seihneider, S., Geiselhart, P., Baumann, F., Siebzehnreubl, S., Fischer, R., and Scheer, H., 1988, Energy transfer in "native" and chemically modified C-phycocyanin trimers and the constituent subunits, in Photosynthetic Light-Harvesting Systems: Structure and Function edited by H.Scheer and S.Schneider, (Berlin: W. deGruyter), pp 469-482.

Zuiber, H., 1986, Primary structure and funetion of the light-harvesting Polypeptides from cyanobacteria, red algae, and prurple photosynthetic bacteria, in Encyclopedia of Plant Physiology, Vol. 19, Photosynthesis III edited by L.A. Staehelin and C.J. Arntzen, (Berlin: Springer), pp. 238-251.

495

Author Index

Abdulaev, N . G . 537 Cordonnier, M . - M . 461, 469 Adam, E . 455 Creager,S.E. 391 Adamse, P. 437 Crossland, L . 461 Ahne, A . 155 Culard,F. 163 Ashman, C R . 193 Alkinson, G .H . 547 Dardalhon,M. 933 Averbeck. D. 933 Davies, R.E. 663 Aziz i , E . 723, 897 Dayhaw-Barker, P. 693

DeFabo, C.E. 763 Bai, U . 411 Deutsch, M . 293 Barker, F . M . 693 Diffey,B.L. 653 Battista, J.R. 177 Donnelly, C.E. 177 Beer, J.Z. 43 Drobetsky, E .A . 35 Ben-Hur,E. 847 Drumm-Herrel, H . 445 Berg, K . 821 Berger, M . 49 Eckardt-Schupp, F. 155 Bergström, H . 367 Edelson, R. 951 Biolo, R. 839 Ehrenberg, B. 815 Björn, L .O . 715 Erokhina, L . G . 511 Blan, Q.A. 795 Estevenon, A . M . 149 Bonazzola, C. 435 Evans, H.H. 83 Borek, C. 1027 Bornman, J.F. 287 Fejes, E. 455 Brash, D. 183 Ferguson, M . 249 Braslavsky, S.E. 435 Fettinger, J. 391 Bredberg,A. 183 Fieser, G. 635 Briggs, W . R . 615 Forbes, P.D. 663

Forlot, P. 925 Frackowiak, D. 511

Cadet,J. 49 Frentz, G. 743 Chadwick, K . H . 71 Fujita, Y . 511 Chaitchik, S. 293 Charlier, M . 163 Gabor, G. 267 Chou, I.-N. 727 Gallagher, S. 615 Cimino, G.D. 249 Gamper, H.B. 249

1073

Gasparro, F.P. 901,951 Keyse, S .M. 861 George, J.C. 597 Kiefer, J. 61 Gerberick, G.F. 671 Kierdaszuk, B . 115 Gev, H . 581 K i m , I.-S. 411 Glickman, B.W. 35 Kirmaier, C. 391 Goldman, B.D. 581 Klapper, B . 573 Goldminz, D. 951 Kobayashi, T. 561 Grebert, P. 163 Kohen, C. 305 Grosovsky, A.J . 35 Kohen, E . 305 Grossweiner, L.I. 795 Koornneef, M . 437 Groves, G.A. 903,909 Koshihara, S. 561

Kraemer, K . H . 183,211 Haim, A . 591 Kripke, M . L . 735 Haupt, W. 479 Krutmann, J. 749 Hader, D.-P. 329,497 Kushelevsky, A . P. 723, 897, 1023 Hara,R. 561 Kuwabara, M . 355 Hearst, D J . E . 249 Kvam, E. 821 Heldmaier,G. 573 Hieda,K. 355 L a i , L - W . 27 Hirschberg, J.G. 305 Lange, W. 379 Hockwin, 0 . 787 Laskowski, M . 615 Holten, D. 391 Latarjet, R. 1, 15 Hovig, E. 821 Leenhouts, H.P. 71

Lehmann, A.R. 21 Ibers, J.A. 391 Levi , G. 591 Ichimura, K . 561 Ley, R.D. 719 Isaacs, S T . 249 Lindemann, P. 435 Ito, T. 105, 345, 355 Lit t le ,J .B. 97

Lopez-Juez, E. 437 Jacobson, E.D. 1057 Luger, T.A. 749 Jay, F .A. 401 Lusky, A . 723 John, T . M . 597 Johnson, B.E. 1045 Magana-Schwencke, N . 933 Johnson, M.R. 391 Mager, H I . X . 319 Jor i ,G. 839 Mah, M . C - M . 199 Joshi, P.C. 49 Mäher, V . H . 199

Malik, Z. 815 Kajil, Y . 435 M a r k , U . 635 K a n , L.-S. 49 Markwell, J.P. 411 Kandori,H. 521 Martin, R.F. 135 Karagiannes, J.L. 795 Mascotto, R.E. 889 Kendrick, R.E. 437 Maurizot, J.-C. 163

1074

McCormick, J.J. 199 Rohatgi-Mukherjee, K . K . 3, 1069 Mcheileh, A . 305 Romanowski, M . 511 Mennigmann, H.-D. 1015 Rosenstein, B.S. 27 Menter, J . M . 873 Rosenthal, I. 847 Milanesi, C. 839 Rüdiger, W. 423 Mimuro, M . 511 Ryan, C A . 671 Minegishi, A . 355 Mitaku, S. 537 Saarela, S. 573 Moan,J . 821 Saile, M . 635 Modan, M . 897 Sambuco, C.P. 663 Mohr, H . 445 Santamaria, L . 975 Moore, C . L . 873 Sargentini, N.J . 169 Moraes, E . C 861 Schachtschabel, D.O. 305 Moustacchi, E . 223 Schaffner, K . 435 Mörschel, E . 379 Schatz, G . -H. 379 Murray, V . 135 Scheer, H . 491

Schewach Millet, M . 897 Nagy, F. 455 Schewach-Millet, M 723 Niedbalska, M . 511 Schifano, M J . 795 Nitzan, Y . 815 Schmidt, J. 787 Nohmi, T. 177 Schmitt, C. 787 Noonan, F.P. 763 Schwarz, T. 749

Seidman, M . M . 183 Obermaier, S. 155 Sessler,J.L. 391 Oesterhelt, D. 531 Setlow, R .B . 17 Ogasawara, K . 561 Settharam, S. 183 Ohtani, H . 561 Shapiro, B . L . 305

Shaw, A . 49 Pay ,A . 455 Shekter, L .R. 35 Peak,J.G. 854 Shichida, Y . 521 Peak, M J . 854 Short, T.W. 615 Pedrini, A . M . 141 Shugar, D. 115 Peters, J.L. 437 Sicard,N. 149 Petkanchin, I.B. 277 Simmons, E. 951 Pottier, R. 807 Skandalis, A . 35 Pratt, L . H . 461,469 Smith, K . C 169

Song, P.-S. 411 Rado,R. 581 Spikes, J.D. 831 Reddi,E. 839 Spirito, F. 141 Riklis, E . 1011, 1069 Spotheim-Maurizot, M . 163 Rodighiero, G. 961 Stolarski, R. 115 Rodriguez, J. 391 Sullivan, J .H. 625

1075

Summers, B . 917 van Grondelle, R. 367 Summers, R.S. 917 van Henegouwen, G.M.J.B 683 Sundström, V . 367 Vogelmann, T.C. 287 Sykes, S .M. 1057 Voituriez, L . 49 Szurkowski, J. 511

Wagner, R. 49 Takakura,K. 355 Walker, G.C. 177 Tamai, N . 511 Wax, Y . 723 Taneva, S.G. 277 Weingold, D. 951 Teramura, A . H . 625 Weinreb, A . 293 Terauchi, M . 561 Wendel, S. 155 Terkel,J. 581 Wesselius, J.C. 437 Tevini, M . 635 Whitelam, G. C. 411 Tornaletti, S. 141 Williamson, G.D. 873 Townsel, M . E . 873 Will is , I. 873 Truscott, T.G. 237 Tsuda, M 537,561 Yamazaki,Y. 511 Tsuda, T. 537 Yang, J.-L. 199 Tu, S.-C 319 Yoshizawa, T. 521 Tyrrell, R . M . 861 Young, A .R. 717

Urbach, F. 705,761,1037 Zamansky, G.B. 727 Urbanski, A . 749 Zhang,Z. 795

Zigman, S. 769 Valduga,G. 435,839 Zinth ,W. 531 van der Leun, J.C. 1033 Zisapel,N. 607

1076

Subject Index

Only principal keywords are listed in the first page of each article. Absorbance 807 Absolute absorption spectrum 521 Acclimatization 591 Action spectrum 1057 Acyclonucleosides

photosynthesis 115 Phosphorylase inhibitors 115

Adaptochromes 491 Adenine, N-oxide

photorearrangement 115 isoguanine analogues 115

A d i a n t u m 479 Aggregation 491 Alcohols

photoaddition to purines 115 Alkali-labile sites 854 5-Alkyluracil nucleosides 115

Photorearrangements 115 Photodimers 115

Allyluracil nucleosides photosynthesis 115

Anthocyanin synthesis 437 Antigen presenting cells 763 Applications 43 A r a b i d o p s i s 437 Azelaic acid 305

B a c i l l u s s u b t i l i s 1015 Bacteria 815 Bathorhodopsin 521 Benzo(a)pyrene 975 Biliprotein 491 Bilirubin 491 Bioluminescence, bacterial 319 Bird 573 Blacklight lamps 653 Blind mole rat 581 Blue

light 287,615

this Subject Index. The page numbers refer to

membrane 249 photoreceptor 437

B lue/UV photoreceptors 445 coaction 445

Broad spectrum 909 BrUdR 135

Cab gene expression 413 Cancer diagnosis 293 Carcinogenesis 43, 1057 ß-carotene Carotenoids 237

ß-carotene 237 canthaxanthin 237

Cataract model 787 Cell

counting 329 culture 861 damage 43 scanning 293 survival 71

tracking 329 Chemical sunscreens 917 Chemiluminescence 267, 319 Chlordiazepekide olaquindox 683 Chlorofluorocarbons 625 Chloroplast

development 437 orientation 479

Circadian 573,581 rhythm 455

Ciinical trial 1045 Cockayne Syndrome 21 C02-gas exchange 635 Coaction (phytochrome-cryptochrome)

479 Cold exposure 597 Cross-links 223

1077

Cryptochrome 437,479 C r y p t o m o n a s 497 Cucumber 437 Cyanobacteria 379 Cytokines 749 Cytoplasmic Streaming 479 Cytosine photohy drates 115

transamination 115 photochemical cross-linking 115

Cytotoxicity 43, 105 Cytotoxic quinone 873

DeadSea 1023 De-etiolation 437 Deexcitation 491 Defense 861 Dendrilic cells 763 Dentistry 653 Deuteroporphyrin 815 Dewar valence isomers 115 Diazepam 683 2,6-Dimethyl-4-aminopyridine 115

photorearrangement 115 7,8-diol-9,10-epoxide of benzo(a)pyrene

199 Direct and indirect effects of ionizing radiation 49 DNA

base damage 43,49 crosslinks 933 damage 135 double Strand breaks 71,97 micro structure 135 monoadducts 931 protein crosslinks 27, 854 repair 141,155,211,951 Strand breaks 27,345 topoisomerase 141

Double Strand breaks 43,61, Drugs 1045

products 663 DSB 854

End-of-day far-red light 437 Electric

light scattering 249 moments 249 Parameters 277

Electromagnetic spectrum 43 Electrophoresis analysis 329 Electron transfer 873 Endogenous gene 35 Energy

intake 591 transfer 491

Epidemiology 787 Erythema 719, 1057 E s c h e r i c h i a c o l i 169

gamma radiation mutagenesis U V radiation mutagenesis 169

E u g l e n a g r a c i l i s 497 Eukaryotic cells 931 Excision repair 149, 223 Excitation energy 367 Excited State 521 Excitonic coupling 491 Exobiology 1015 Exposure 653 Far-UV radiation 49 Fibre optics 287 Flagellates 497 Flavanoids 635 Flavin, electron transfer and

luminescence 319 Fluorescence 491,635, 807

lifetimes polarization 293, 491 probes 305

Foerster transfer 491 Food industry 653 Food intake 591 Free radicals 355 Furocoumarins 931

Gamma radiation 169 mutagenesis (E. c o l i ) 169

Gene expression 437

1078

Glutathione 861 Gravitaxis 497 Greenfinch 573 GroEL 177 GroES 177 G y r o d i n i u m 329

Hematoporphyrin derivative 815 Herne oxygenase 861 Herpes Simplex Virus type I 763 History 43

ofmedicine 211 Human 861

cell 183, 199 cell lines 27

Hybrid 491 Hydroxybenzenes 873 Hyperplasia 719

ICR2A cell lines 27 Image analysis 497 Immobilization 511 Imuno-N-oxide 683 Immunosuppression 749, 763 I n v i t r o 807 I n v i v o 807 Inducible response 155 Industrial photoprocesses 653 Infrared 903 Insect traps 653 Interaction (phytochrome-cryptochrome)

479 process 71

Interactions 43,61 Internal

con version 491 light gradients 287

Ionizing radiation 61,71 Isoguanosine, photosynthesis 115 Isomerization, c i s - t r a n s 423 IUdR 135

Jablonski diagram 237

Keratinocytes 749

l a c repressor - l a c Operator System 163 Laser flash photolysis 237 Lasers 653 Legislation 1045 Lens 787 Librium 683 Light

harvesting 379 inducted gene expression 455 perception 491 scattering 795 Stimulus 581

Loblolly pine ( P i n u s taedä) 625 Locomotor activity 581 Look-up-tables 329 Luciferase

bacterial 319 mechanism 319

Luminescence 267 Lymphocytes 293,949

8-MOP = 8-methoxypsoralen 975 Mammalian cells 61, 193 Marsupial 719 M a s t i g o c l a d u s l a m i n o s u s 491 MB255 human melanoma cells 305 Melanin 873 Melanoma 719 Melatonin treatment 597 5-membered retinal 521 7-membered retinal 521 Microorganisms 1015 Molecular ecology 491 Monoadducts 223 M o u g e o t i a 479 M s e o t a e n i u m 479 Mutagenesis 43, 169, 199

back mutations 169 base Substitution 169

1079

E . c o l i 169 frameshift 169 oxygen-dependent 169 oxy gen-independent 169 recA-dependent 169 suppressor mutations 169 transitions 169 transversions 169 wmwC-dependent 169 wmwC-independent 169

Mutagenicity 933 Mutants 437

a u r e a 437 high pigment 437 photoreceptor 437 response 437 transduction chain 437 yellow-green 437

Mutational hotspots 193 specificity 35

Mutations 97

1-nitropyrene 199 N-acetoxy-2-acetulaminofluorene 199 NAD(P)H 305 Naphthalocyanines 831 Natural Killer cells 21 Neoplastic transformation 43 Non-shivering thermogenesis (NST)

591 Non-stochastic effects 1057

OER 169 OHradical 105 Oligonucleotide degradation 345 Oligoribonucleotides 115

synthesis, 115 v i a photosensitive ö-nitrobenzyl

groups 115 Operating theatres 653 Oxaziridine 683 Oxidative D N A lesions...49

Oxygen effect 169 enhancement ratio 169

Ozone 1027

Panspermia 1015 pBR322 D N A 355 PESTsequence 423 Pfr appearance 393 pH 807 Pharmacokinetics 787 Phosphorylation 615 Phosphate-buffered saline 27 Photoacoustic 511 Photoactivation 719,815 Photoadduct 951 Photoaffinity labeling, 115

direct 115 cross-linking 115

Photoallergy 683, 1045 Photobleaching 831 Photocarcinogenesis 663 Photochemistry 491

of l a c repressor 163 Photochemoprotection 925 Photochemotherapy 653 Photodynamic

effects 49,847 therapy 787,831

Photoisomerization 521 Photometabolism 683 Photomorphochromes 437,491 Photoperiod 591 Photopharmacology 683 Photophoresis, 951 Photophysics 491 Photoprotection 873 Photoreactivating light 27 Photoreactivation 141 Photorhodopsin 521 Photosensitization 795, 831, 1045 Photosynthetic purple bacteria 367 Phototaxis 497 Phototherapy 653 Phototoxicity 1045

1080

Phototropism 445, 615 coaction of photoreceptors 445

Phthalocyanines 847,831 Phycobilisome 491, 511 Phycocyanin 491 Phycoerythrocyanin 491 Phycoviolobilin 491 Phytochrome 393, 423, 437, 445, 479,

491 regulated gene expression 455 Ubiquitin 393

Picosecond absorption spectrum 521 fluoresecne kinetics 521

Pigeons 597 breathing frequency 597 heartrate 597 oxygen consumption 597 shivering 597 temperature 597

Pinealectomy 597 Planetary quarantine 1015 Plant growth 635 Plant photoreceptor 423 Polarized spectra 511 Porphyrin 807,815 Post-irradiation repair 71 Primary lesions 43 Primary photoprocess 561 Protection 861 Protein conformation 423 Proteins 861 pso 1 gene 223 pso 2 gene 223 Psoralens 925,933,951

photoadducts 223 Psoriasis 1021 Pubescence 287 Pulse radiolysis 237 Purine

1,6-dihydro-6-hydroxymethyl 115 Purine riboside (nebularine)

1,6-dihydro-6-hydroxymethyl 115 Purine nucleosides 115

conformation 115 C(8) addition of isopropanol 115

8,5'-cyclo-8-oxy analogues 115 Purple membrane 249 Purple membrane fragments 277 P U V A 949 Pyrimidine dimer 719

unwinding angle 141 Pyrimidine-2 115

Electrochemical reduction 115 Photodimers 115

Photodissociation 115

Quinoxaline-1,4-dioxides 683

Radicals 237 O H - 237 B r 2 . - 237 N 3 . 237

R A D 3 223 R A D 6 223 R A D 52 223 Radiation chemistry 237 Radiationless deactivation 491 Radical Anion 237 Radical cation 237 Reaction kinetics 873 Redalgae 379 Regulation 1033, 1045 Repair 61,933 Retinochrome 561 Retroviral Shuttle vector 35, 193 Rhythm 573, 591 Ribonucleotide reductase 115

B l subunit 115 Photochemical cross-linking to

dTTP 115 Cysteinyl-thymine photoadduct,

structure 115 Risk management 1057 Risks 1033

S. p n e u m o n i a e 149 Saccharomyces c e r e v i s i a e 155

1081

Seasonal 573 Seed germination 437 Sensory rhodopsin 561 Sequence specificity 135 Shuttle vector 183, 199 Signal transduction 615 Single oxygen 237 Singlet oxygen 787 Siskin 573 Skin 1043

Cancer 211,719 photoreceptor 763

S-nucleosides, pyrimidine photorearrangement 115

Sodium dodecyl sulfate 27 Sodium dodecyl sulfate 249 Solar U V 861

spectral measurements 1023 Solvated Electron 237 Soybean ( G l y c i n e m a x ) 625 Space 1015 Spectra 511 Spectroscopy 807 SPF 903 Spin-trapping 355 Spores 1015 SSB 854 Sterilization 653 Stochastic effects 1057 Stratospheric ozone (depletion) 625 Stress 861 Subcellular lesions 43 Sunbathing 653, 1023 Sunbeds 653 Sunburn cells 719 Sunflower 635 Sunlight 653 Sunscreens 903,909,925

agents 917 preparations 917

Superexcited State 345 s u p F gene 199 Suppressor T cells 763 Synchrotron radiation 105, 345

Tanning 653,925 Temperature 573,1015 Testing 1047 Tetrapyrrole chromophore 423 Thermoregulation 573, 597 Thymine-cystein photoproducts 115

cross-linking 115 monoanion 115 photoreaction with alkylamines 115 -ly sine photoadduct 115

Time resolved emmision 511 spectroscopy 561

Tissue-specific gene expression 455 Tomato 437 TpT

(6-4) photoproduct 115 cyclobutane photodimers 115 Dewar valence isomer of, 115

Transformations 97 Transgenic tobacco 455 Trichothiody strophy 21 Tryptophan photooxydation 163 Tumors 831 Tumor promoters 97 Tyrosinase 873

UmuDC 177 Urocanic acid 763 U V mutagenesis 177, 183

Uracil nucleoside photohydrates 115 alkaline dehydration 115 ring-opened intermediate 115

Ultrastructural studies 787 Ultra-violet 135,211

adaptations 625 B radiation 625,635 cytotoxicity 71 damage and D N A superstructure 141 filters 917 irradiated cell lines 27 light 97,749

1082

mutagenesis 155 ( E . c o l i ) 169

radiation 169, 287, 497, 787, 1033 risk assessment 1057

U V A 854,861,909 U V B 135, 763, 854, 861 U V - C type damage 105

Vision 521 V U V

photolysis 355 photoproduct 345 radiation 345

Welding 653

Vacuum 1015 action spectra 105 light 49 U V 43,355

Valium 683 V a l l i s n e r i a 479 V e r b a s c w n thapsus 287 Very low fluence response 437 Video digitization 329

Xeroderma pigmentosum 21,211 X-ray type damage 105

Yeast 61, 141, 155 transformation 933

Zn(II)-phthalocyanine 787

1083