ADP-ribosylation of a specific protein from isolated intact bull testis nuclei.

ADP-ribosylation of a specific basic protein has been investigated in isolated intact bull testis nuclei incubated with NAD+. The electrophoretic mobility, molecular weight and amino-acid composition of the purified bull testis specific protein are similar to those of rat testis protein. About 1-5% of the total radioactivity incorporated in the 20% acid-insoluble fraction was associated with testis protein and was identified as ADP-ribose.