McCauley T C, Bellin M E, Ax R L
Department of Animal Sciences, University of Arizona, Tucson 85721, USA.
J Anim Sci. 1996 Feb;74(2):429-38. doi: 10.2527/1996.742429x.
Heparin-binding proteins (HBP) in bull seminal fluid bind to epididymal sperm membranes at ejaculation. Peptides recognized by a monoclonal antibody (M1) correspond to proteins identified in complexes that have the greatest affinity for heparin and are present on sperm from bulls with higher fertility. Presence of specific HBP on sperm regulates the ability of sperm to bind heparin, and heparin binding to sperm correlates with the fertility potential of a bull. In these studies, the interaction of HBP with sperm from 10 bulls of proven fertility was analyzed by immunofluorescence of M1 to determine the localization of heparin-binding proteins during capacitation, and the fluorescent binding patterns were compared to bull nonreturn rates. Immunofluorescent localization of M1 binding sites revealed the existence of specific membrane domains containing HBP in acrosomal and postacrosomal regions of ejaculated but not in epididymal sperm. Monoclonal antibody recognition of HBP localized on membranes of sperm revealed variable binding patterns of M1 to the acrosomal region in sperm from bulls of known fertility. Regression analysis indicated a negative relationship between sperm displaying exclusively acrosomal fluorescence and bull nonreturn rate. These data indicate that HBP bind to sperm in distinct patterns, one of which differed among bulls of varying fertility, and indicate no apparent relocalization of these sites during cellular changes that occur in preparation for fertilization.
公牛精液中的肝素结合蛋白（HBP）在射精时与附睾精子膜结合。单克隆抗体（M1）识别的肽段对应于在对肝素具有最高亲和力的复合物中鉴定出的蛋白质，并且存在于生育力较高的公牛的精子上。精子上特定HBP的存在调节精子结合肝素的能力，而肝素与精子的结合与公牛的生育潜力相关。在这些研究中，通过M1的免疫荧光分析了HBP与10头经证实具有生育力的公牛的精子之间的相互作用，以确定获能过程中肝素结合蛋白的定位，并将荧光结合模式与公牛的返情率进行比较。M1结合位点的免疫荧光定位显示，在射出精子的顶体和顶体后区域存在含有HBP的特定膜结构域，而附睾精子中则不存在。对精子膜上HBP的单克隆抗体识别显示，已知生育力的公牛精子中M1与顶体区域的结合模式存在差异。回归分析表明，仅显示顶体荧光的精子与公牛返情率之间呈负相关。这些数据表明，HBP以不同模式与精子结合，其中一种模式在不同生育力的公牛之间存在差异，并且表明在为受精做准备的细胞变化过程中，这些位点没有明显的重新定位。
