Picosecond laser cross - linking histones to DNA in chromatin: implication in studying histones - DNA interactions

D. Angelov, S. Dimitrov, E. Keskinova, I. Pashev, V. Russanova, Yu Stefanovsky

Research output: Contribution to journalArticle


A picosecond UV laser radiation was used to cross - link proteins to DNA in nuclei, whole cells and different chromatin preparations. All histones as well as high - mobility group 1 proteins were identified immunochemically in the covalently linked protein - DNA complexes. Irradiation of the nucleohistone resulted in cross - linking 20% of bound histones to DNA as a result of two - quantum photoreaction with a maximum quantum yield 3.10-4 for double stranded DNA. When nuclei, total hromatin, H1 - depleted chromatin and core particles were irradiated and then trypsinized or treated with clostripain to cleave respectively the N-, C- and N- terminal histone tails, no histones were found covalently linked to DNA. However whilst the yield of cross - links was similar in total and H1 - depleted chromatin in core particles the efficiency was 3 - 4 times lower for H2A, H2B and H4 and 10 - 12 times lower for H3.

Original languageEnglish
Pages (from-to)230-239
Number of pages10
JournalProceedings of SPIE - The International Society for Optical Engineering
Issue numberpt 1
Publication statusPublished - 1991
Externally publishedYes


ASJC Scopus subject areas

  • Electrical and Electronic Engineering
  • Condensed Matter Physics

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