[Reaction between tetranitromethane and deoxyribonucleoproteins].

A comparative kinetic study has been made of tetranitromethane nitration of tyrosine residues in deoxyribonucleoprotein preparation (DNP) treated with EDTA and/or UV light at lambda=253.7 nm, as well as obtained by enzymatic digestion of nucleosomes. UV-light-induced protein-DNA linkages stabilize the structure of the preparation, whereas the action of chelate agents causes DNP-200 angstrom leads to DNP-100 angstrom transfer. Comparison of kinetic data and the results of the amino acid analysis of individual fractions of nitrated histones allowed to conclude that the differences observed between the degree and the rate of nitration are due to internucleosomic interactions which form the supernucleosomic structure of DNP.