[Study of DNA complexes with a synthetic fragment of histone H4 and polypeptide (Gly-Orn-Gly)n]

Complexes of DNA with synthetic N-terminal peptide of histone H4 (A-13) and with poly(Gly-Orn-Gly) in 0.015 M NaCl solution have been studied by means of viscometry, light scattering and circular dichroism. The process of intramolecular compactization begins to occur at a low content of poly(Gly-Orn-Gly) in complexes, while in the case of A-13 compactization takes place only when the content of A-13 in complexes attains 13--14%. Intermolecular aggregation of both complexes takes place with the increase of peptide content in the complexes. Intramolecular compactization and aggregation do not influence the local conformation of DNA as revealed by CD spectra. The possible mechanism of these peptide-DNA interactions suggested.