[Study of nystatin effect on nuclear proteases of dog kidney causing degradation of acid-soluble proteins of chromatin].

A relationship between the previously observed degradation of dog kidney chromatin histones induced by polyene antibiotics, and a change in enzymatic activity of neutral histone protease or proteases localized on the outer nuclear membrane was studied. It was shown that in the course of proteolysis of chromatin isolated from the nuclei after treatment by Triton X-100 nistatin inhibits neutral histone proteases as can be evidenced from the amount of the amino groups formed and the data of electrophoretic analysis of chromatin histones. The inhibitory effect of nistatin is sharply enhanced with an increase in its concentration. It is found that in the course of proteolysis of chromatin isolated from the nuclei untreated with Triton X-100, nistatin increases the degree of acid-soluble protein degradation. The latter effect is probably due to the stimulation of the enzymatic activity of proteases localized on the outer nuclear membrane by nistatin.