title: Mapping the heparin-binding domain of boar spermadhesins.
abstract: Boar spermadhesins are a group of seminal plasma, heparin-binding proteins which appear to be involved in sperm capacitation and gamete interaction. Using a proteolytic protection assay we have identified regions of AQN-1, AQN-3, PSP-I and AWN which remain attached to a heparin-Sepharose column following in-column digestion of bound spermadhesins with chymotrypsin and elastase. In addition, the complete amino acid sequence of spermadhesin AWN was synthesized as overlapping peptides, and their ability to bind to a heparin-Sepharose column and to inhibit the interaction of soluble heparin with purified ELISA plate-coated AWN was tested. Both approaches gave similar results and as a whole showed that different regions of AWN may converge in its tertiary structure to form a composite heparin-binding site. The conformational heparin-binding surface resides on the GFCC'C'' face of the proposed structural model for AWN and is in an opposite location to the carbohydrate-binding region of the spermadhesin.
authors.affiliation: Institut für Reproduktionsmedizin, Tierärztliche Hochschule, Hannover,Germany.
authors.forename: J J
authors.initials: JJ
authors.lastname: Calvete
authors.forename: Z
authors.initials: Z
authors.lastname: Dostàlova
authors.forename: L
authors.initials: L
authors.lastname: Sanz
authors.forename: K
authors.initials: K
authors.lastname: Adermann
authors.forename: H H
authors.initials: HH
authors.lastname: Thole
authors.forename: E
authors.initials: E
authors.lastname: Töpfer-Petersen
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D002352:Carrier Proteins / Q000737:chemistry* / Q000378:metabolism; D006023:Glycoproteins / Q000737:chemistry / Q000378:metabolism; D006493:Heparin / Q000378:metabolism*; D008297:Male; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000737:chemistry* / Q000378:metabolism; D010449:Peptide Mapping; D012661:Semen / Q000737:chemistry* / Q000378:metabolism; D029589:Seminal Plasma Proteins; D029607:Seminal Vesicle Secretory Proteins; D015842:Serine Proteinase Inhibitors / Q000737:chemistry / Q000378:metabolism; D013552:Swine
chemical_list: D002352:Carrier Proteins; D006023:Glycoproteins; D010446:Peptide Fragments; D029589:Seminal Plasma Proteins; D029607:Seminal Vesicle Secretory Proteins; D015842:Serine Proteinase Inhibitors; C425042:spermadhesin; C074520:seminal vesicle secretory protein 109, porcine; D006493:Heparin