de Lamirande Eve
Urology Research Laboratory, Royal Victoria Hospital, Faculty of Medicine, McGill University, Montréal, Québec, Canada.
Semin Thromb Hemost. 2007 Feb;33(1):60-8. doi: 10.1055/s-2006-958463.
Semenogelin (Sg), the main component of the human semen coagulum, is an important and versatile protein acting on several sperm parameters, both as intact or degraded Sg. Sg originates mostly from seminal vesicle and probably is responsible for sperm immobilization in the seminal coagulum. Purified Sg can be cross-linked by transglutaminase or phosphorylated by kinases, but the actual occurrence of these reactions in reproductive physiology is not clear. Experimental evidence demonstrates that prostate-specific antigen (PSA) rapidly cleaves Sg, an event temporally associated with semen liquefaction and initiation of sperm motility. Sg and its degradation peptides participate in various processes including Zn +2 shuttling, antibacterial activity, hyaluronidase activation, and so on. Sg inhibits sperm motility at the concentration found in the coagulum, but the rapid processing by PSA allows initiation of movement. The mechanism of Sg action and its targets are not known, but improper Sg degradation decreases fertility. Sg and its degradation peptides block sperm capacitation and associated events at concentrations much lower than those of seminal plasma and could play important role in preventing premature capacitation. The effects of Sg are dependent on time and proteolysis due to PSA, and any imbalance may affect sperm physiology and fertility.
精液凝素（Sg）是人类精液凝块的主要成分，是一种重要且功能多样的蛋白质，无论是完整的还是降解的Sg，都对多种精子参数有影响。Sg主要来源于精囊，可能负责精液凝块中精子的固定。纯化的Sg可被转谷氨酰胺酶交联或被激酶磷酸化，但这些反应在生殖生理学中的实际发生情况尚不清楚。实验证据表明，前列腺特异性抗原（PSA）能快速裂解Sg，这一事件在时间上与精液液化和精子运动的启动相关。Sg及其降解肽参与多种过程，包括锌离子穿梭、抗菌活性、透明质酸酶激活等。Sg在凝块中发现的浓度下会抑制精子运动，但PSA的快速作用可使精子开始运动。Sg的作用机制及其靶点尚不清楚，但Sg降解不当会降低生育能力。Sg及其降解肽在浓度远低于精浆的情况下就能阻断精子获能及相关事件，可能在防止过早获能中发挥重要作用。Sg的作用取决于时间和PSA引起的蛋白水解，任何失衡都可能影响精子生理和生育能力。
