Heparin-binding proteins of seminal plasma in Nellore bulls

O objetivo deste estudo foi identificar proteínas ligadoras à heparina no plasma seminal de touros Nelore (Bos taurus indicus). Para tanto, foram selecionados quatro touros entre 30 e 36 meses de idade e peso aproximado de 500-550kg. Após centrifugação, amostras do plasma seminal foram misturadas e as proteínas ligadoras à heparina foram isoladas por meio da cromatografia por afinidade. As frações após a eluição foram agrupadas para caracterização das bandas protéicas (SDSPAGE, 12,5%). Foram identificadas oito bandas protéicas variando entre 15 e 63kDa. Duas proteínas com 22 e 25kDa foram similares às descritas em touros Bos taurus taurus. Outras proteínas identificadas com 39, 53, 58 e 63kDa ainda não foram descritas e possivelmente sejam específicas para Bos taurus indicus.

Abstract (english)

The aim of this study was to identify heparin-binding proteins (HBPs) in seminal plasma of Nellore (Bos taurus indicus) bulls. Bulls (n=4), 30-36 months old, 500-550kg with satisfactory seminal quality were selected. After the centrifugation, samples of the seminal plasma were pooled and the HBPs were isolated by heparin-affinity chromatography. The recovered HBPs fractions were pooled. One-dimensional sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDSPAGE) 12.5% was performed in vertical minigels. Eight bands with molecular weights ranging from 15 to 63kDa were observed. Two proteins were identified (22 and 25kDa), similar to those previously described in Bos taurus taurus bulls. Other bands identified in this study (39, 53, 58 and 63kDa) have not been previously observed and possibly they are specific to Nellore semen.