AMINO-ACID-SEQUENCE OF BETA-MICROSEMINOPROTEIN FROM PORCINE SEMINAL PLASMA

beta-Microseminoprotein is a small mucus-associated protein of unknown function, previously characterized in man and the ape. The correspond ing porcine protein was identified in tracheal mucus and seminal plasm a by its cross-reaction with antibodies raised against the human prote in. The porcine protein was isolated from seminal plasma, and its comp lete amino acid sequence determined. It is a single-chain protein of 9 1 amino acids with a molecular mass of 10,068 Da. Compared to primate beta-microseminoprotein, the porcine protein has a blocked N-terminus and a deletion of three amino acids in the N-terminal region, but othe rwise manifests similarity in amino acid sequence including conservati on of 10 cysteine residues. A proportion of individual pigs have two f orms of the protein, differing in charge but not in size. The characte rization of beta-microseminoprotein in a species suited for experiment s should help determine the function of this protein. (C) 1995 Academi c Press. Inc.