Ammonia-activated sea urchin egg chromatin-bound proteolytic activity
Sánchez-Chiang, L.; Ponce, O.; Merino, V.
Biochemistry International 8(2): 237-244
1984
ISSN/ISBN: 0158-5231 PMID: 6383399 Document Number: 228965
Chromatin from ammonia activated sea urchin eggs contains a proteolytic activity capable of hydrolyzing urea denatured casein at pH 8.0. The soluble fraction, obtained by treatment of chromatin with 0.7 M NaCl, presents a proteolytic activity which is about 16 times higher than that of the corresponding fraction from unfertilized eggs. Moreover, the SDS-PAGE profile of the soluble fraction from the ammonia activated eggs presents a greater number of bands and exhibits two groups of non histone proteins migrating near histone H1. The soluble proteolytic activity selectively digests certain non histone proteins of high and low molecular weight and histone H1 from the same fraction. Digestion products are formed. The effects of PMSF, sodium bisulfite and NaCl suggest the presence of more than one proteolytic activity in the soluble fraction from activated eggs. Our results sport the regulatory role of this enzyme activity based on the selective degradation of chromatin proteins.