Heparin-binding proteins of canine seminal plasma

Abstract

Heparin-binding proteins (HBP) from seminal plasma have been expected to participate in modulation of the acrosomal reaction, and have been correlated with fertility in some species. However, they have not been described in the dog. The aim of this study was to document the HBPs of canine seminal plasma. Six pooled samples of seminal plasma from three crossbred dogs were used. The HBPs were isolated by heparin affinity chromatography and the fractions recovered were pooled. One-dimensional sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) was carried out on 12 and 18% vertical minigels. The stained gels were scanned and the molecular weight (kDa) values for each band within a lane were calculated by image analysis software. The electrophoresis analysis of the pooled eluded fractions identified 19 bands, with molecular weights varying from 61.5 to 5.2 kDa. Previous studies, using one-dimensional SDS-PAGE, identified two bands (67 and 58.6 kDa), which were positively correlated with some semen parameters (sperm motility, sperm vigor, percentage of morphologically normal sperm and plasma membrane integrity). The 61.5 kDa band detected in the present study apparently corresponded to the 58.6 kDa band identified previously. Canine seminal plasma contained HBP; since HBP modulate the acrosome reaction in other species, they may have the same function in the dog. Further studies are necessary to better characterize this protein and determine if it is associated with fertility in the dog.

Semen parameters and seminal plasma protein and biochemical profiles of dogs with benign prostatic hyperplasia after botulinum toxin type A intraprostatic injection

“…Arginine esterase, also known as canine prostate specifi c protein (CPSE) is a protein with enzymatic activity that is found in high concentrations in the canine prostatic fl uid and has been associated with fertility (MCENTEE et al, 1987;SOUZA et al, 2006). Previous reports suggested that the 15kDa band may be a subunit of the arginine esterase (SOUZA, 2003).…”

Influence of the Prostatic Fluid from the First and Third Fractions of the Ejaculates on the Cryosurvival of Poodle Dog Sperm

“…These proteins appear to participate in the bovine sperm membrane lipid modifications that occur during Capacitation [39] . De Souza and coworkers [28] reported that the proteins resembling BSP were found in crossbred dog seminal plasma (58.6, 67 and 61.5 kDa). However, these investigators did not show whether these proteins were present in all fractions of the ejaculates or if they were only found in prostatic fluid.…”

“…Boisvert et al [27] also isolated and characterized homologous proteins from bison seminal vesicle secretion (BiSV-16, BiSV-17, BiSV-18 and BiSV-28 kDa). Furthermore, De Souza et al [28] identified these heparin-binding proteins, particularly the 61.5 kDa protein, in the prostate secretions of 3 crossbred dogs and investigated whether these proteins were involved in the acrosome reaction of sperm. Cross [2] reported that prostasomes that are expelled from the prostate gland at ejaculation contain large amounts of cholestero and the fusion between prostasomes and sperm enriches the sperm membrane in cholesterol, thereby delaying the acrosome reaction and decreasing membrane fluidity [1,3,29] .…”

Proteins of the canine seminal plasma

“…HBPs bind to the spermatozoa surface after ejaculation and affect fertility due to their modulatory role during the acrosome reaction (MANJUNATH et al, 1993). SOUZA et al (2006), using heparin affinity chromatography followed by one-dimensional electrophoresis (12% and 18% SDS-PAGE), reported that 19 protein bands of the canine SP bound to the heparin column. Of these 19 proteins, a 61.5kDa protein was particularly thought be involved in the canine acrosome reaction (SOUZA et al, 2006).…”