Excited State Interactions and Photochemical Reactions in Protein-Nucleic Acid Complexes

Abstract

Protein-nucleic acid complexes are of central importance in molecular biology. The expression of genetic information and its regulation require the formation of such highly specific complexes. An investigation of the excited states and of the photochemical behavior of these complexes has different purposes: i) excited state properties may be used to obtain information on the mechanism of complex formation and on the nature of molecular interactions involved in these complexes; ii) the study of photochemical reactions in protein-nucleic acid complexes should help us understand the action of UV radiations on biological systems; iii) the formation of photochemical cross-links between a protein and a nucleic acid in a specific complex should provide information on the regions of the two macromolecules which are in close contact in the complex. The use of photochemical cross-linking reactions should be comparable to that of bifunctional chemical reagents with the advantage that the photochemical reaction directly links two chemical groups one on each macromolecule.