title: Proteases of nuclei of testicular cells assayed with fluorogenic peptides.
abstract: Nuclei of seminiferous epithelial cells (SEC) of rat testis exhibit protease activity when assayed with fluorogenic peptides or with [3H]histones. At pH 8 the nuclear protease rapidly hydrolyzes BOC-Val-Pro-Arg-7-Amino-4-Methyl Coumarin (BVPAC) and Glu-Gly-Arg-7-Amino-4-Methyl Coumarin (GGAC), but this enzyme does not hydrolyze CBZ-Arg-7-Amino-4-Methyl Coumarin (CAC) or Glu-Phe-7-Amino-4-Methyl Coumarin (GPC). The cytoplasm of these cells hydrolyzes each of these substrates. The protease activity versus BVPAC can be extracted from cytoplasm and nuclei with 0.1 M H2SO4. The extracted activity from cytoplasm is lost during storage for 5 days at either pH 3 or pH 8 at -25 degrees, but the activity extracted from nuclei is maintained under these conditions. The nuclear protease activity is found in SEC of young rats prior to the appearance of acrosin.
mesh_terms: D000818:Animals; D002467:Cell Nucleus / Q000201:enzymology; D002918:Chymotrypsin / Q000378:metabolism; D003593:Cytoplasm / Q000201:enzymology; D005456:Fluorescent Dyes; D006863:Hydrogen-Ion Concentration; D008297:Male; D010447:Peptide Hydrolases / Q000378:metabolism*; D010455:Peptides / Q000378:metabolism; D051381:Rats; D011919:Rats, Inbred Strains; D012670:Seminiferous Epithelium / Q000201:enzymology* / Q000648:ultrastructure; D012741:Sexual Maturation; D013737:Testis / Q000201:enzymology*; D014357:Trypsin / Q000378:metabolism
chemical_list: D005456:Fluorescent Dyes; D010455:Peptides; D010447:Peptide Hydrolases; D002918:Chymotrypsin; D014357:Trypsin