Nonenzymic acetylation of histones with acetyl phosphate and acetyl adenylate

Nonenzymatic acetylation of calf-thymus lysine- and arginine-rich histones was demonstrated to occur when these proteins were incubated with 14Cacetyl phosphate and 14Cacetyl adenylate. The levels of acetylation depend on both pH and on reagent concentration. When acetyl 33Pphosphate and acetyl 3Hadenylate were used as reagents, we found neither histone phosphorylation nor adenylylation. Most of the radioactivity of 14C-labeled acetylated histones was recovered as Ne-acetyllysine. Furthermore, only a small amount of O-bound radioactivity was released by the 14C-labeled acetylated arginine-rich histone during treatment with hydroxylamine. Experiments on the acetylation of histones, in the presence of increasing salt concentration, gave different results for the two acetylating agents.