title: Diisopropylfluorophosphate-interacting proteinases of nuclei of rat testis cells.
abstract: Nuclei and chromatin of seminiferous epithelial cells of rat testis contain acid-extractable and non-extractable proteins which interact readily with [3H]DFP (diisopropylfluorophosphate). Proteinase activity is closely associated with these DFP-interacting proteins, and the proteinase activities are inhibited by DFP and PMSF. DFP-interacting proteins of testis chromatin increase greatly in amount at 26-32 days after birth when spermatids are appearing in increasing numbers. In nuclei separated by zonal centrifugation on sucrose gradients, the DFP-labeled proteins are highest in activity in the elongated spermatids at the stage in spermiogenesis at which histones are being replaced by testis-specific proteins and protamines. Electrophoresis in SDS-polyacrylamide gels reveals the presence of three species of DFP-interacting proteins in nuclei of seminiferous epithelial cells of the testis. The chromatin of epididymal spermatozoa of the rat contains three or four species of DFP-interacting proteins by SDS-polyacrylamide electrophoresis and some of these labeled proteins co-migrate with two of the three basic proteins which are observed during electrophoresis on polyacrylamide gels in Triton-urea.
mesh_terms: D000367:Age Factors; D000818:Animals; D002467:Cell Nucleus / Q000201:enzymology*; D002843:Chromatin / Q000201:enzymology; D007531:Isoflurophate / Q000494:pharmacology; D008297:Male; D010447:Peptide Hydrolases / Q000378:metabolism*; D011480:Protease Inhibitors; D051381:Rats; D013737:Testis / Q000201:enzymology*
chemical_list: D002843:Chromatin; D011480:Protease Inhibitors; D007531:Isoflurophate; D010447:Peptide Hydrolases