Collect. Czech. Chem. Commun. 1984, 49, 1204-1210

Disulfide bonds of basic acrosin inhibitor (BUSI II) from bull seminal plasma

Alena Rzavskáa, Bedřich Melouna and Dana Čechováb

a Institute of Organic Chemistry and Biochemistry
b Institute of Molecular Genetics, Czechoslovak Academy of Sciences, 166 10 Prague 6


The thermolysin digest of the basic acrosin inhibitor (molecular weight 6 200) was resolved on a column of Sephadex G-15 and subsequently by electrophoretic and chromatographic techniques. Cysteine peptides, which link together half-cysteine residues 7 and 39, 17 and 36, and 25 and 57 by disulfide bonds, were isolated. The structure of the molecule of the basic acrosin inhibitor corresponds to structures of inhibitors of the Kazal type. The amino acid sequence of a few residues in the basic acrosin inhibitor has been revised.