Further studies of a thymus nucleohistone-associated protease.

摘要: Abstract The endogenous proteolytic degradation of the histones calf thymus nucleohistone has been followed with polyacrylamide disc gel electrophoresis and dansylation amino-terminal amino acids. enzyme is tightly associated nucleohistone, essentially inactive below pH 7.0, decreased in activity at lower ionic strengths, shows a rather specific bond cleavage for those histone fractions which are susceptible to its attack, inactivated by brief heat treatment (2 min 90°). susceptibility five proteolysis critically dependent upon whether form complex or not DNA. In intact three groups almost totally resistant attack while lysine-rich sulfhydryl-containing rapidly attacked. If freed from DNA, only fraction protease; all other degraded. general tissues having high cell turnover, e.g. intestinal mucosa, exhibit greater rate than observed tissue. reversibly inhibited either presence sodium bisulfite storing low strength (∼5 x 10-4).