Influence of tetrapeptide on chromatin thermostability.

It is known that short peptides are capable to interact with DNA, as a result of changes in particular gene expression. In the given work, influence of Ala-Asp-Glu-Leu peptide on thermostability of white rat liver chromatin, in which H1 histone and non-histone proteins are depleted, have been studied. It was shown that in 10 nm chromatin filaments, in which nucleosomas do not interact, the tetrapeptide unfolds the nucleosomal nucleus (core) and this causes release of about 15% of core DNA that melts in the melting temperature range of internucleosomal linker DNA. Thus, the studied tetrapeptide can increase accessibility of DNA for transcription.