The concept of using photochemical probes in the study of biological systems was developed by Westheimer who published the first photoaffinity labeling experiments more than twenty years ago (J.Bio1. Chem. 237, (1962) 3006). Since then the concept has been used successfully in various areas of biochemistry and recently several new interesting and exciting aspects of the concept have been developed. It is the general opinion by scientists in the "field" that the full potential of photochemical probes in biochemical studies has far from been exploited yet. This is mostly due to the interdisciplinary character of the concept involving photochemistry, synthetic chemistry as well as biochemistry/molecular biology. The perspective of the NATO advanced workshop on "Photochemical Probes in Biochemistry", held in Holte (Copenhagen) Denmark 14-19, August, 1988, was several fold. The workshop was to give an account of the "state of the art" of using photochemical probes in biochemistry as well as to bring together specialists in photochemistry, syn­ thetic chemistry and molecular biology in order to analyze advantages as well as the inherent problems and pitfalls of the concept and provide suggestions and guidelines for fu­ ture research. Furthermore, it is the hope of the editor that the present publication which gives an account of the lectures presented at the workshop, will provide an introduction to scientists who are not familiar with photochemical probes, but to whom these could help answer central and pertinent questions.

Inhalt

1. Photolabeling Reagent Design.- 2. Nucleophilic Aromatic Photo Substitutions on Nitrophenyl Ethers. A New Photoaffinity Labelling Technique.- 3. Photochemistry of Aryl and Aroyl Azides: Application to Photo-labeling of Biological Systems.- 4. Membrane Protein Labelling with Photoreactive Phospholipid Analogues.- 5. 125J-ASA-PE, A Photoactivable, Radioactive Phospholipid-Analogue, Designed for Photolabeling Proteins in Contact with Phospholipid Head Groups. Selective Photolabeling of Subunits ? in Thermophilic ATPsynthase TF0.F1.- 6. Photoaffinity Labelling of Receptors of Melanocyte-Stimulating Hormone.- 7. Topographical Analysis of the Torpedo Marmorata Acetylcholine Receptor by Energy Transfer Photoaffinity Labeling Using Aryldiazonium Derivatives.- 8. Photosuicide Labelling.- 9. Antibiotic Photoaffinity Labeling Probes of Escherichiacoli Ribosomal Structure and Function.- 10. Dissection of the Ribosomal Peptidyl Transferase Center by Photoaffinity Labeling: P- and A-sites are Located at Different Positions in Domain V of 23 S RNA:.- 11. Studying the Cytoskeleton by Label Transfer Crosslinking: Uses and Limitations.- 12. RecA-Directed Hybridization of Psoralen-Monoadducted DNA Oligonucleotides to Duplex Targets.- 13. The Use of Psoralen-Photocrosslinking for the Analysis of the Chromatin Structure during Transcription.- 14. Metal Complexes as Photochemical Probes of DNA Structure.- 15. Laser-Induced Strand Break Formation of Polyuridylic Acid in the Presence and Absence of Tris (2,2?-Bipyridyl) Ruthenium Chloride and K2S2O8.- 16. Photonucleases.- 17. Sequence-Targeted Photochemical Reactions in Single-Stranded and Double-Stranded Nucleic Acids by Oligonucleotide-Photosensitizer Conjugates.- 18. Photofootprinting Analysis of Protein-DNA Interactions.- 19. Studies of the Binding and Biological Actions of Ethidium.- 20. Quantitative Photoaffinity Labeling of Escherichiacoli RNA Polymerase Transcription Complexes by Nascent RNA.- 21. "Caged" Compounds to Probe the Dynamics of Cellular Processes: Synthesis and Properties of some Novel Photosensitive P-2-Nitrobenzyl Esters of Nucleotides.- General Comments on the Use of Photochemical Probes in Biochemistry. Advantages, Problems and Pitfalls.- List of Participants.- Author Index.- Keyword Index.