Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P56851 (epididymal)
 11,273 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Heparin binds to bovine sperm and stimulates capacitation in vitro. Seminal plasma alters the ability of epididymal sperm to bind heparin, and several heparin-binding proteins (HBPs) have been identified in bull seminal plasma. This study had three objectives: 1) to identify production sites of seminal plasma HBPs, 2) to determine which HBPs bound to cauda epididymal sperm, and 3) to determine whether presence of HBPs was testosterone dependent. Proteins from bull or rat seminal vesicles, prostates, and bulbourethral glands were separated by heparin affinity high-performance liquid chromatography. HBPs were found in all accessory glands of rats and bulls, but the major source of bovine seminal plasma HBPs appeared to be seminal vesicles. Between 25% and 50% of the protein from each gland bound to the heparin column, and NaCl concentrations required to elute proteins ranged from 0.15 to 1.4 M. One-dimensional sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) showed that major HBPs were relatively small, with molecular weights between 13 and 31 kDa, but some HBPs also exhibited higher molecular weights, between 40 and 100 kDa. Radioiodinated HBPs from each bovine gland were incubated with epididymal sperm. Labeled HBPs binding to sperm exhibited molecular weights of 14, 16, 24, and 30 kDa as determined by SDS-PAGE and autoradiography. The HBP content of the accessory sex glands decreased significantly in castrated rats and was restored to levels of sham-operated controls by testosterone replacement. Heparin-binding proteins may play a role in fertilization by attaching to sperm surfaces, enabling heparin-like glycosaminoglycans in the female reproductive tract to induce capacitation.
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PMID:Male accessory sex glands produce heparin-binding proteins that bind to cauda epididymal spermatozoa and are testosterone dependent. 233 73

PDC-109 (13 kDa) is the most abundant component, and the major heparin-binding protein, of bovine (Bos taurus) seminal plasma. Here, we show that PDC-109 contains a single O-linked oligosaccharide (NeuNAc alpha(2-6)-Gal beta(1-3)-GalNAc-) attached to Thr11. Immunoquantitation of PDC-109 indicates that its concentration in seminal plasma is 15-20 mg/ml. Though PDC-109 is not present on epididymal sperm, ejaculated spermatozoa on average are coated with (9.5 +/- 0.3) x 10(6) molecules of PDC-109/cell. This value remained constant in swim-up sperm and decreased to (7.7 +/- 0.4) x 10(6)/spermatozoon after incubation for 24 h in capacitation medium at 39 degrees C. These data substantiate the hypothesis that PDC-109 may be one of the seminal plasma components that enhance the fertilizing capacity of bull spermatozoa upon interaction with heparin-like glycosaminoglycans present in the female genital tract.
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PMID:Localization and structural characterization of an oligosaccharide O-linked to bovine PDC-109. Quantitation of the glycoprotein in seminal plasma and on the surface of ejaculated and capacitated spermatozoa. 807 May 64

Presence or absence of three distinct bovine seminal heparin-binding proteins (21-31 kDa) recognized in sperm extracts by a monoclonal antibody, M1, is a diagnostic indicator of fertility differences among bulls producing normal semen. We recently identified a 31 kDa fertility-associated antigenin bovine seminal fluid as a unique DNase I-like protein. We now report purification and identification of a 24 kDa seminal heparin-binding protein (HBP-24) recognized by M1. N-terminal microsequence analysis of HBP-24 purified from seminal fluid yielded 20 amino acid residues that displayed 90% identity to the N-terminus of a bovine metalloproteinase inhibitor identified as tissue inhibitor of metalloproteinases-2 (TIMP-2). A single immunoreactive band migrating at 24 kDa was detected in Western blots of cauda epididymal sperm extracts following incubation with purified seminal heparin-binding proteins and subsequent washing in vitro, indicating TIMP-2 bound to sperm membranes. Expression of TIMP-2 mRNA was detected by RT-PCR in bovine bulbourethral gland, prostate, and seminal vesicles. Mobility of the 24 kDa heparin-binding protein increased under nonreducing SDS-PAGE to approximately 21 kDa, characteristic of the reported molecular mass of TIMP-2. To our knowledge, this is the first report of TIMP-2 binding to spermatozoa and of TIMP-2 mRNA expression in bovine accessory sex glands. These results corroborate previous reports regarding the site of production of heparin-binding proteins that are related to bull fertility, and suggest that TIMP-2 influences fertility of bulls, either through inhibition of metalloprotease activity in semen or via undefined activities independent of matrix metalloproteinase (MMP) inhibition.
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PMID:Identification of a heparin-binding protein in bovine seminal fluid as tissue inhibitor of metalloproteinases-2. 1117 Feb 75