Characterization of a polypeptide from human seminal plasma with inhibin (inhibition of FSH secretion)-like activity

Abstract

A polypeptide in preparations of ‘large’ form ( M r ∼14 000) material with inhibin-like activity (inhibiting FSH secretion) has been isolated from human seminal plasma. Its amino acid composition, cleavage pattern with CNBr, N-terminal sequence, and properties on reverse-phase high-performance liquid chromatography establish this inhibin-like preparation to be homogeneous. The polypeptide contains close to 130 residues, has a free N-terminal serine residue, a methionine residue in position 19, and a dibasic structure (Arg—Lys) in positions 16–17.