title: Bovine proacrosin from cauda epididymal sperm: purification, characterization and partial sequencing at N-terminus.
abstract: 1. In the present study, we isolated the two forms of proacrosin from acid extracts (pH 3.0) of cauda epididymal bovine spermatozoa by ammonium sulfate fractionation, gel filtration on Sephadex G-150 and affinity chromatography on Concanavalin A Sepharose 4B. The overall purification was 13-fold with respect to crude acid acrosomal extract. 2. The apparent molecular weight of the proacrosins determined by SDS-PAGE were 44,000 and 38,000. Both forms have proteinase activity on gelatin-SDS-polyacrylamide gel electrophoretic zymography. 3. The M(r) = 38,000 component was isolated by reverse phase HPLC. Thirty-nine amino acid residues at the N-terminus have about 72 and 77% sequence similarity with boar and human proacrosin, respectively. 4. The amino acid sequence of 14 amino acids at the N-terminus of the high molecular weight component (M(r) = 44,000) was determined after electroblotting on a polyvinylidene difluoride membrane. This portion of the molecule is identical with that of the low molecular weight component. 5. Proacrosin autoactivation followed the sigmoidal activation curve.
authors: Institute for Enzyme Research, University of Wisconsin, Madison 53705.
authors: S K
authors: SK
authors: NagDas
mesh_terms: D000176:Acrosin / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism; D000595:Amino Acid Sequence; D000818:Animals; D002118:Calcium / Q000494:pharmacology; D002417:Cattle; D004789:Enzyme Activation; D004792:Enzyme Precursors / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism; D004822:Epididymis / Q000201:enzymology; D006801:Humans; D066298:In Vitro Techniques; D007700:Kinetics; D008297:Male; D008969:Molecular Sequence Data; D008970:Molecular Weight; D017386:Sequence Homology, Amino Acid; D013045:Species Specificity; D013094:Spermatozoa / Q000201:enzymology*; D013552:Swine
chemical_list: D004792:Enzyme Precursors; C022438:proacrosin; D000176:Acrosin; D002118:Calcium