Vainio P, Thurén T, Wichman K, Luukkainen T, Kinnunen P K
Biochim Biophys Acta. 1985 Apr 11;814(2):405-8. doi: 10.1016/0005-2736(85)90463-8.
Monomolecular films of phospholipid were used to study the interaction of intact human spermatozoa with model membranes. Exclusively with negatively charged phosphatidylglycerol monolayers rapid penetration of spermatozoa into the monolayer with subsequent hydrolysis of the lipid was triggered by the addition of 5 mM calcium into the medium. The results suggest the localization of a calcium-dependent phospholipase A2 at the outer acrosomal or plasma membrane of human spermatozoa with its active site exposed to the external environment. Preincubation of the cells with 100 microM gossypol completely abolished the ability of human spermatozoa to hydrolyze or penetrate monolayers of phosphatidylglycerol. The inhibition of the phospholipase activity by gossypol may contribute to the unknown contraceptive mechanisms of this non-steroidal male antifertility agent.
磷脂单分子膜被用于研究完整人类精子与模型膜的相互作用。仅在带负电荷的磷脂酰甘油单分子层中，向培养基中添加5 mM钙会引发精子迅速穿透单分子层并随后使脂质水解。结果表明，钙依赖性磷脂酶A2定位于人类精子顶体或质膜外部，其活性位点暴露于外部环境。用100 microM棉酚对细胞进行预孵育完全消除了人类精子水解或穿透磷脂酰甘油单分子层的能力。棉酚对磷脂酶活性的抑制作用可能有助于解释这种非甾体类男性抗生育剂未知的避孕机制。
