Biopolymers and cell. 1994. Volume 10. № 1. 41 - 46

R. G. Primak, A. G. Goriushko, E. L. Levitsky, Yu. I. Gubsky, S. N. Novikova

STUDY OF CONFORMATIONAL CHARACTERISTICS OF TRANSCRIPTIONALLY ACTIVE AND REPRESSED CHROMATIN BY MEANS OF FLUORESCENT PROBES

Summary

    Conformational characteristics of transcriptionally active and repressed chromatin fractions from rat liver were studied by means of pyrene probe and 1,8-ANS. It was shown that there observed inductive-resonance energy transfer (IRET) between chro¬matin protein chromophores and the pyrene molecules, which were introduced to the solution; this allowed to conclude about some structural parameters of protein-lipid interactions. Probability of energy transfer from protein fluorophores to pyrene and the portion of protein tryptophane residues, which took part in IRET, were calculated. Marked differences in the values of the parameters stated for the chromatin fractions observed allowed to conclude about less compact package of the active fraction, which was the necessary premise for the launching and realization transcriptional process, as well as about the dependence of this process on the character of the interaction of proteins and lipids in chromatin.