Premium
Visible Light Irradiation of Ethidium Bromide–stained Interphase Nuclei Causes DNA–Protein Linking and Structural Stabilization of Nucleoprotein Complexes ¶
Author(s) -
Prusov Andrey N.,
Kireev Igor I.,
Polyakov Vladimir Yu.
Publication year - 2003
Publication title -
photochemistry and photobiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.818
H-Index - 131
eISSN - 1751-1097
pISSN - 0031-8655
DOI - 10.1562/0031-8655(2003)0780592vlioeb2.0.co2
Subject(s) - nucleoprotein , chromatin , ethidium bromide , interphase , histone , dna , non histone protein , chemistry , biophysics , microbiology and biotechnology , biology , biochemistry
Fixation of DNA and proteins in the isolated rat hepatocyte nuclei stained with ethidium bromide and irradiated with visible light was analyzed in this study. It was shown that irradiation results in the following modifications of higher‐level nucleoprotein complexes of interphase chromatin: (1) the complexes acquire resistance to decondensing treatments, which may be indicative of the formation of links between proteins or proteins and DNA in the chromatin; (2) the linking rate for both DNA and proteins is dose dependent; (3) the irradiation induces intermolecular link formation between DNA molecules, which brings about an increase in the average molecular weight of DNA fragments; (4) some modifications (dimerization, etc. ) of histones and nonhistone proteins occur; and (5) histone proteins are not effectively cross‐linked to DNA. The structural stabilization of interphase chromatin is possibly mediated by free radical–based mechanisms, whereas disulfide bonds seem to play no significant role in the cross‐linking.