Barua M, Bhattacharyya U, Majumder G C
Biochem Int. 1985 May;10(5):733-41.
Intact spermatozoa from goat cauda epididymis possess phosphoprotein phosphatase activity that causes dephosphorylation of externally added [32p]histones. The enzymic reaction was linear with time for at least 15 min and there was little uptake of [32p]histones by these cells. The activity of the enzyme of the whole spermatozoa was not due to contamination of the broken cells or epididymal plasma and leakage of the intracellular enzymic activity during incubation. The activity of the phosphoprotein phosphatase was strongly inhibited by the thiol reagent: p-chloromercuribenzenesulfonic acid, which is believed not to enter the cells. There was no appreciable loss of the enzymic activity from the cells when washed with EDTA (2.0 mM) or a hyperosmotic medium. These data are consistent with the view that the observed activity of the enzyme is located on the spermatozoal external surface. Studies with unlabelled p-nitrophenyl phosphate and beta-glycerophosphate indicate that the sperm ecto-enzyme is not a non-specific phosphatase.
来自山羊附睾尾部的完整精子具有磷蛋白磷酸酶活性，可使外源添加的[32P]组蛋白发生去磷酸化。酶促反应至少在15分钟内呈线性，这些细胞对[32P]组蛋白的摄取很少。整个精子的酶活性并非由于破碎细胞或附睾血浆的污染以及孵育期间细胞内酶活性的泄漏。磷蛋白磷酸酶的活性受到硫醇试剂对氯汞苯磺酸的强烈抑制，据信该试剂不会进入细胞。用EDTA（2.0 mM）或高渗培养基洗涤后，细胞的酶活性没有明显损失。这些数据与以下观点一致，即观察到的酶活性位于精子外表面。对未标记的对硝基苯磷酸酯和β-甘油磷酸酯的研究表明，精子外酶不是非特异性磷酸酶。
