Boar Acrosin II. CLASSIFICATION, INHIBITION, AND SPECIFICITY STUDIES OF A PROTEINASE FROM SPERM ACROSOMES

摘要: Abstract Acrosin, a proteolytic enzyme located in the acrosome of sperm, exhibits amidase, esterase, and proteinase activity on synthetic natural substrates containing arginyl lysyl residues. Highly purified acrosin preparations from boar acrosomes have endopeptidase cleaving only carboxyl bonds arginine lysine with strong preference for bonds. The Michaelis constant hydrolysis benzoyl ethyl ester at pH 8.0 is 5 x 10-5 m. inhibited by diisopropyl fluorophosphate tosyl chloromethyl ketone, indicating that serine histidine residues may be present active site. Acrosin several inhibitors appears to unique its amidase esterase activities are competitively free an apparent Ki 3 mm. unusual specificity implications biological role sperm penetration zona pellucida ovum.