Manjunath Puttaswamy, Thérien Isabelle
Department of Medicine, University of Montreal and Guy-Bernier Research Center, Maisonneuve-Rosemont Hospital, 5415 Blvd. de L'Assomption, Montreal, Québec, Canada H1T 2M4.
J Reprod Immunol. 2002 Jan;53(1-2):109-19. doi: 10.1016/s0165-0378(01)00098-5.
Bovine seminal vesicles secrete a family of similar proteins designated BSP-A1, BSP-A2, BSP-A3 and BSP-30-kDa (collectively called bovine seminal plasma (BSP) proteins). The biochemical properties of these proteins are well documented and considerable progress has been made concerning their biological role. At ejaculation these BSP proteins bind to the sperm surface. The binding sites on the sperm surface have been identified as choline phospholipids (specifically phosphatidylcholine (PC), phophatidylcholine plasmalogen (PC plasm) and sphingomyelin (SPM)) composed of sperm plasma membrane. Our previous studies have shown that the BSP proteins interact specifically with heparin and high-density lipoproteins (HDL), the capacitation factors in bovine. In addition, we have shown that the BSP proteins potentiate epididymal sperm capacitation induced by heparin and HDL. Recently, we showed that the BSP proteins stimulated cholesterol and phospholipid efflux from the sperm membrane. Furthermore, the lipid efflux from sperm is dependent on BSP protein concentration and duration of incubation. The loss of membrane cholesterol is an important step in the capacitation process. These results together indicate that BSP proteins play an important role in sperm membrane lipid modification events that occur during sperm capacitation.
牛精囊分泌一类相似的蛋白质，命名为BSP-A1、BSP-A2、BSP-A3和BSP-30-kDa（统称为牛精浆（BSP）蛋白）。这些蛋白质的生化特性已有充分记载，并且在其生物学作用方面已取得了相当大的进展。射精时，这些BSP蛋白会与精子表面结合。精子表面的结合位点已被确定为精子质膜中的胆碱磷脂（特别是磷脂酰胆碱（PC）、磷脂酰胆碱缩醛磷脂（PC缩醛磷脂）和鞘磷脂（SPM））。我们之前的研究表明，BSP蛋白与肝素和高密度脂蛋白（HDL）特异性相互作用，HDL是牛的获能因子。此外，我们还表明，BSP蛋白可增强由肝素和HDL诱导的附睾精子获能。最近，我们发现BSP蛋白可刺激精子膜中胆固醇和磷脂的流出。此外，精子的脂质流出取决于BSP蛋白的浓度和孵育时间。膜胆固醇的流失是获能过程中的一个重要步骤。这些结果共同表明，BSP蛋白在精子获能过程中发生的精子膜脂质修饰事件中起重要作用。
