Isolation of Basic Acrosin Inhibitor from Bull Seminal Plasma (BUSI II)

Abstract
An acrosin inhibitor was isolated from bull seminal plasma by gel filtration on Sephadex G-50 fine and ion-exchange chromatography on CM-Sephadex. The inhibitor is a basic polypeptide (pI [isoelectric point] .gtoreq. 10.5) of MW 6200 (calculated from amino acid composition). Its N-terminal amino group is blocked. The inhibitor is not strictly specific in its effect since it also inhibits trypsin [EC 3.4.21.4] and to a lesser degree chymotrypsin [EC 3.4.21.1], in addition to bull and boar acrosin.