Isolation and characterization of heparin- and phosphorylcholine-binding proteins of boar and stallion seminal plasma. Primary structure of porcine pB1.
In the bovine, seminal plasma heparin-binding proteins bind to sperm lipids containing the phosphorylcholine group and mediate the capacitating effects of heparin-like glycosaminoglycans during sperm residence in the female genital tract. We report the characterization of heparin- and phosphorylcholine-binding proteins of stallion and boar seminal plasma. Horse seminal plasma proteins HSP-1 and HSP-2, and boar protein pB1, belong to the same family as the bull heparin- and phosphorylcholine-binding proteins BSP-A1/2, BSP-A3, and BSP-30K. We have determined the amino acid sequence and posttranslational modifications of boar glycoprotein pB1. It contains 105 amino acids arranged into a mosaic structure consisting of a N-terminal 18-residue O-glycosylated polypeptide followed by two tandemly organized 40-45-residue fibronectin type II domains. pB1 displays 60-65% amino acid sequence similarity with its equine and bovine homologues. However, in their respective seminal plasmas, the BSP and the HSP proteins associate into 90-150-kDa oligomeric complexes, whereas pB1 forms a 35-40-kDa complex with spermadhesin AQN-1. In addition, pB1 appears to be identical to the recently described leukocyte adhesion regulator of porcine seminal fluid pAIF-1. Our results tie in with the hypothesis that homologous proteins from different mammalian species may display distinct biological activities, which may be related to species-specific aspects of sperm physiology.
Calvete
J J
JJ
Institut für Reproduktionsmedizin, Tierärztliche Hochschule Hannover,Hannover-Kirchrode, Germany. jcalvete@repro.tiho-hannover.de
Raida
M
M
Gentzel
M
M
Urbanke
C
C
Sanz
L
L
Töpfer-Petersen
E
E
D000595:Amino Acid Sequence; D000818:Animals; D002352:Carrier Proteins / Q000737:chemistry*; D006023:Glycoproteins / Q000737:chemistry*; D006031:Glycosylation; D006493:Heparin / Q000378:metabolism*; D006736:Horses; D008297:Male; D008969:Molecular Sequence Data; D010449:Peptide Mapping; D010767:Phosphorylcholine / Q000378:metabolism*; D012661:Semen / Q000737:chemistry*; D029589:Seminal Plasma Proteins; D017421:Sequence Analysis; D017386:Sequence Homology, Amino Acid; D013045:Species Specificity; D013552:Swine; D008562:Membrane Glycoproteins
D002352:Carrier Proteins; D006023:Glycoproteins; D006493:Heparin; D010767:Phosphorylcholine; D029589:Seminal Plasma Proteins; C095321:HSP-1 protein, Equus caballus; C106240:HSP-2 protein, Equus caballus; C121098:BSP1 protein, Sus scrofa; D008562:Membrane Glycoproteins