Zinc-binding proteins from boar seminal plasma - isolation, biochemical characteristics and influence on spermatozoa stored at 4°C

摘要

Affinity chromatography on Chelating Sepharose FastFlow Gel-Zn2+ was used for fractionation of boar seminalplasma proteins. Approximately 30 % of total boar seminalplasma proteins showed affinity for zinc ions (ZnBPfraction). Native electrophoresis (PAGE) of ZnBP revealedsix protein fractions which separated into 27 bands underdenaturing conditions (SDS/PAGE). Two-dimensionalelectrophoresis (2D PAGE) showed 148 polypeptideswith isoelectric points mostly in the basic and neutral pHrange. The zinc-binding proteins comprise mainly 10–20kDa polypeptides which are probably members of thespermadhesin family. ZnBP present in the incubationmixture of spermatozoa stored for 1 or 24 h at 4 °C allowedpreservation of a higher percentage of cells exhibitinglinear motility in comparison to a control samplestored in PBS. Presented results indicate that proteinsbinding Zn2+ ions have a shielding effect on the spermplasma membrane and acrosome of spermatozoa, protectingthese structures against consequences of coldshock.