Immunological identification of seminalplasmin in tissue extracts of sex glands of bull.

Using immunoglobulin G (IgG) antibodies raised against highly purified, homogeneous seminalplasmin, an antimicrobial protein of bovine seminal plasma, it has been shown that bovine ampullae, gland vesicularis and corpus prostate, but not testes and epididymis, contain seminalplasmin. The content as estimated by radioimmunoassay employing 125I-seminalplasmin was: ampullae, 267 +/- 13; gland vesicularis, 275 +/- 14; and corpus prostate, 445 +/- 22 micrograms per g wet weight of the tissue. Seminalplasmin, as characterized by high-performance liquid chromatography and in vivo inhibition of RNA synthesis in E. coli, was isolated from gland vesicularis. The seminalplasmin content of bovine seminal plasma was shown to be 1%. A chymotryptic peptide of seminalplasmin comprising residues 1-13 from the amino terminus was found to compete with 125I-seminalplasmin for binding to anti-seminalplasmin IgG.