title: Purification and characterization of prolyl endopeptidase from the Pacific herring, Clupea pallasi, and its role in the activation of sperm motility.
abstract: Protease activities with specificity toward synthetic substrates, Suc-Gly-Pro-Leu-Gly-Pro-MCA for prolyl endopeptidase or collagenase-like peptidase, and Suc-Ala-Ala-Pro-Phe-MCA for chymotrypsin were identified in the detergent-soluble fraction of herring spermatozoa. The enzyme activities increased in the presence of herring sperm-activating protein (HSAP). Among them a prolyl endopeptidase [EC. 3. 4. 21. 26] was purified to near homogeneity from herring testis. The molecular mass of the enzyme was 79 kDa and the properties of the enzyme were quite similar to prolyl endopeptidase from other tissues or cells. Both the enzyme activation and the sperm motility activation by HSAP were inhibited by benzyloxycarbonyl-L-thioproline-thioprolinal, a specific inhibitor for prolyl endopeptidase. Furthermore, the motility activation by HSAP was inhibited by substrates of the prolyl endopeptidase. Western blotting with mouse anti-prolyl endopeptidase serum revealed the presence of 79 kDa prolyl endopeptidase in the tail fraction of herring sperm. These results suggest that prolyl endopeptidase exists on the surface of the sperm tail and interacts with the HSAP.
authors.affiliation: Misaki Marine Biological Station, Graduate School of Science, University of Tokyo, Kanagawa, Japan. ucchi@mmbs.s.u-tokyo.ac.jp
authors.forename: K
authors.initials: K
authors.lastname: Yoshida
authors.forename: K
authors.initials: K
authors.lastname: Inaba
authors.forename: H
authors.initials: H
authors.lastname: Ohtake
authors.forename: M
authors.initials: M
authors.lastname: Morisawa
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D002852:Chromatography, Ion Exchange; D004591:Electrophoresis, Polyacrylamide Gel; D005399:Fishes; D008297:Male; D008969:Molecular Sequence Data; D000085822:Prolyl Oligopeptidases; D017386:Sequence Homology, Amino Acid; D012697:Serine Endopeptidases / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D013081:Sperm Motility / Q000187:drug effects*; D013552:Swine
chemical_list: D012697:Serine Endopeptidases; D000085822:Prolyl Oligopeptidases