Purification and Characterization of Heparin Binding Proteins from Seminal Plasma of Cross- bred Cattle Bulls by Affinity Chromatography, SDS-PAGE and Mass Spectrometry

Heparin binding proteins (HBP) play a crucial role in the fertility of bovine semen. In this study HBPs purified from cross-bred cattle bull seminal plasma (SP) by sepharose-affinity chromatography were characterized by SDS-PAGE, and mass- spetrometery. Affinity chromatographic analysis indicated two peaks of unbound (non-HBP) and bound proteins (HBP). On average, seminal plasma of cross-bred bulls contained 39.36 ± 4.41% HBP with a peak area of 2.74 ± 0.82 cm2. Sixteen bands with molecular weights ranging from 14 kDa to 150 kDa could be separated by SDS-PAGE from seminal plasma of 11 bulls. SDS-PAGE analysis of the eluted HBP peaks identified 14 bands, with molecular weights ranging from 14 kDa to 150 kDa. However, variation in number of bands, separated in SP and SP-HBP was observed among the bulls. The matched peptides of 60; 40, 35; 31, 28; 25 and 20 kDa proteins with highest score (>61-67) were identified to have significant matching with the peptides of Platelet activatin factor AH; Clusterin preprotein; DNase1-L3 and TIMP-2, respectively. This study envisaged that four characterized SP-BHPs have important functions in reproduction. Moreover, role of DNASE-1L-3 and TIMP-2 kDa proteins is related to higher conception rate of bovine. Therefore, this study opens a further scope to analyze these SP – HBP as potential biomarkers of fertility in cross – bred bulls.