SPERM MOTILITY INHIBITOR FROM HUMAN SEMINAL PLASMA - PRESENCE OF A PRECURSOR MOLECULE IN SEMINAL-VESICLE FLUID AND ITS MOLECULAR PROCESSING AFTER EJACULATION
SPERM MOTILITY INHIBITOR FROM HUMAN SEMINAL PLASMA - PRESENCE OF A PRECURSOR MOLECULE IN SEMINAL-VESICLE FLUID AND ITS MOLECULAR PROCESSING AFTER EJACULATION
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DOI：
10.1111/j.1365-2605.1994.tb01248.x
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发表时间：
1994-10-01
影响因子：
--
通讯作者：
GAGNON, C
中科院分区：
文献类型：
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作者：
ROBERT, M;GAGNON, C
人类精浆含有一种蛋白质因子，能够抑制脱膜和完整精子的运动。这种因子“精浆运动抑制剂”（SPMI）已被证明完全来自精囊。目前的结果表明，精子中SPMI的生物活性迅速下降，从1000 U/ml，射精后立即，到220 U/ml 2小时后。精浆蛋白的免疫印迹探测与抗人SPMI的抗体，揭示了一个主要的52 kDa的SPMI抗原，目前在精囊分泌物的快速加工。该前体最初降解为25-40 kDa的中等分子量片段，随后降解为17-21 kDa的较小片段。当精囊液与前列腺分泌物（3：1 v/v）混合时，前列腺分泌物中存在的蛋白酶被证明是负责SPMI前体的加工。添加蛋白酶抑制剂，如苯甲基磺酰氟（PMSF，5 mM），苯甲脒（100 mM）或乙二胺四乙酸（EDTA，5 mM）的混合物的精囊腺和前列腺分泌物部分防止SPMI的活性损失的54%，27%和9%，分别。然而，PMSF和苯甲脒的同时添加赋予SPMI前体活性几乎完全稳定。这些结果表明，SPMI作为主要的52 kDa前体形式存在于精囊中，并在射精后被液化精液中存在的一种或多种前列腺来源的丝氨酸蛋白酶和/或金属蛋白酶迅速加工成活性较低、分子量较低的形式。
Human seminal plasma contains a protein factor that has the capacity to inhibit the movement of demembranated and intact spermatozoa. This factor 'seminal plasma motility inhibitor' (SPMI) has been shown to originate exclusively from the seminal vesicles. The present results demonstrate that the biological activity of SPMI in semen decreases rapidly from 1000 U/ml, immediately after ejaculation, to 220 U/ml 2 h later. Immunoblots of seminal plasma proteins probed with an antibody against human SPMI, revealed the rapid processing of a predominant 52 kDa SPMI antigen, present in the seminal vesicle secretions. This precursor was degraded initially into intermediate molecular mass fragments of 25-40 kDa, and subsequently into smaller fragments of 17-21 kDa. When seminal vesicle fluid was mixed with prostatic secretions (3 : 1 v/v), proteases present in prostatic secretions were shown to be responsible for processing of the SPMI precursor. Addition of protease inhibitors such as phenylmethylsulphonyl fluoride (PMSF, 5 mM), benzamidine (100 mM) or ethylenediaminetetraacetic acid (EDTA, 5 mM) to the mixture of seminal vesicle and prostate secretions partially prevented the loss of activity of SPMI by 54%, 27% and 9%, respectively. However, the simultaneous addition of PMSF and benzamidine conferred almost total stability to the SPMI precursor activity. These results demonstrate that SPMI exists as a predominant 52 kDa precursor form in the seminal vesicles and is processed rapidly after ejaculation into less active, lower molecular mass forms by one or more serine proteases and/or metalloproteases of prostatic origin which are present in liquefied semen.