从山羊附睾血浆中纯化和鉴定精子运动抑制因子。

Purification and characterization of a sperm motility inhibiting factor from caprine epididymal plasma.

机构信息

Indian Institute of Chemical Biology, Kolkata, India.

出版信息

PLoS One. 2010 Aug 10;5(8):e12039. doi: 10.1371/journal.pone.0012039.

DOI:10.1371/journal.pone.0012039

PMID:20706623

原文链接:https://pmc.ncbi.nlm.nih.gov/articles/PMC2919373/

Abstract

Several studies have been reported on the occurrence of sperm motility inhibiting factors in the male reproductive fluids of different mammalian species, but these proteins have not been adequately purified and characterized. A novel sperm motility inhibiting factor (MIF-II) has been purified from caprine epididymal plasma (EP) by Hydroxylapatite gel adsorption chromatography, DEAE-Cellulose ion-exchange chromatography and chromatofocusing. The MIF-II has been purified to apparent homogeneity and the molecular weight estimated by Sephacryl S-300 gel filtration is 160 kDa. MIF-II is a dimeric protein, made up of two subunits each having a molecular mass of 80 kDa as shown by SDS-PAGE. The isoelectric point of MIF-II is 5.1 as determined by chromatofocusing and isoelectric focusing. It is a heat labile protein and maximal active at the pH 6.9 to 7.5. The sperm motility inhibiting protein factor at 2 microg/ml (12.5 nM) level showed maximal motility-inhibiting activity. The observation that the epididymal plasma factor lowered the intracellular cAMP level of spermatozoa in a concentration-dependent manner suggests that it may block the motility of caprine cauda spermatozoa by interfering the cAMP dependent motility function. The results revealed that the purified protein factor has the potential of sperm motility inhibition and may serve as a vaginal contraceptive. The antibody raised against the MIF-II has the potential for enhancement of forward motility of cauda-spermatozoa. This antibody may thus be useful for solving some of the problems of male infertility due to low sperm motility.

摘要

已经有几项研究报告了在不同哺乳动物物种的雄性生殖液中存在精子运动抑制因子，但这些蛋白质尚未得到充分的纯化和表征。一种新型的精子运动抑制因子（MIF-II）已通过羟磷灰石凝胶吸附层析、DEAE-纤维素离子交换层析和等电聚焦从山羊附睾血浆（EP）中纯化出来。MIF-II 已被纯化至明显的均一性，通过 Sephacryl S-300 凝胶过滤估计的分子量为 160 kDa。MIF-II 是一种二聚体蛋白，由两个亚基组成，每个亚基的分子量为 80 kDa，如 SDS-PAGE 所示。MIF-II 的等电点为 5.1，如等电聚焦和等电聚焦所确定。它是一种热不稳定的蛋白质，在 pH 6.9 至 7.5 时活性最大。在 2 μg/ml（12.5 nM）水平下，精子运动抑制蛋白因子表现出最大的运动抑制活性。观察到附睾血浆因子以浓度依赖的方式降低精子的细胞内 cAMP 水平，表明它可能通过干扰 cAMP 依赖性运动功能来阻止山羊尾部精子的运动。结果表明，纯化的蛋白因子具有抑制精子运动的潜力，可作为阴道避孕药。针对 MIF-II 产生的抗体具有增强尾部精子向前运动的潜力。因此，这种抗体可能有助于解决由于精子运动能力低而导致的一些男性不育问题。