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Chemical Phosphorylation of Nucleosomes and Histone H4
Author(s) -
Lin YuanChuan,
Smith Roberts A.
Publication year - 1981
Publication title -
journal of the chinese chemical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.329
H-Index - 45
eISSN - 2192-6549
pISSN - 0009-4536
DOI - 10.1002/jccs.198100039
Subject(s) - phosphoramidate , chemistry , nucleosome , phosphorylation , imidazole , phosphoserine , chromatin , stereochemistry , organic chemistry , biochemistry , dna , serine
Using N,N′ ‐Dicyclohexylcarbodiimide (DCC) as a condensing agent, 32 P‐cyanoethylphosphate and NH 3 were combined to yield 32 P‐cyanoethylphosphoramidate. Treatment with NaOH resulted in a β‐elimination step to yield 32 P‐phosphoramidate and acrylonitrile. The phosphoramidate was purified via DEAE‐cellulose chromatography. At p H 7.4 the histidine residues of histone H4 were chemically phosphorylated using 32 P‐phosphoramidate as the phosphoryl donor. The nucleophilic nitrogen of the imidazole ring is attracted to the phosphorus of phosphoramidate resulting in the displacement of NH 3 and formation of the protein phosphoryl‐nitrogen linkages. Chromatin monomers (nucleosomes) were prepared by a mild digestion of chromatin with micrococcal nuclease. This report also presents the chemical phosphorylation of these nucleosomes by 32 P‐phosphoramidate.