Amino acid sequence of basic acrosin inhibitor from bull seminal plasma

Abstract

The molecule of the inhibitor contains 57 amino acid residues whose sequence is the following: Pyr-Gly-Ala-Gln-Val-Asp-Cys-Ala-Glu-Phe-Lys-Asp-Pro-Lys-Val-Tyr-Cys-Thr-Arg-His-Ser-Asp-Pro-Gln-Cys-Gly-Ser-Asn-Gly-Glu-Thr-Tyr-Gly-Asn-Lys-Cys-Ala-Phe-Cys-Lys-Ala-Val-Met-Lys-Ser-Gly-Gly-Lys-Ile-Asn-Leu-Lys-His-Arg-Gly-Cys-Lys. The N-terminal group of the inhibitor is pyrrolidone carboxylic acid. The sequential data were obtained by analyses of peptides isolated from tryptic and chymotryptic digests of the oxidized or carboxymethylated inhibitor. The molecular weight of the inhibitor is 6 200.