Molecular mechanism of epididymal protease inhibitor modulating the liquefaction of human semen

作者：Wang, Zeng-Jun^*; Zhang, Wei; Feng, Ning-Han; Song, Ning-Hong; Wu, Hong-Fei; Sui, Yuan-Geng

来源：Asian Journal of Andrology, 2008, 10(5): 770-775.

DOI：10.1111/j.1745-7262.2008.00393.x

• epididymal protease inhibitor
• semenogelin
• prostate specific antigen

Aim: To study the molecular mechanism of epididymal protease inhibitor (Eppin) modulating the process of prostate specific antigen (PSA) digesting semenogelin (Sg). Methods: Human Sg cDNA (nucleotides 82-849) and Eppin cDNA (nucleotides 70-423) were generated by polymerase chain reaction (PCR) and cloned into pET-100D/TOPO. Recombinant Eppin and Sg (rEppin and rSg) were produced by BL21 (DE3). The association of Eppin with Sg was studied by far-western immunoblot and radioautography. In vitro the digestion of rSg by PSA in the presence or absence of rEppin was studied. The effect of anti-Q20E (N-terminal) and C-terminal of Eppin on Eppin-Sg binding was monitored. Results: Eppin binds Sg on the surface of human spermatozoa with the C-terminal of Eppin (amino acids 75-133). rSg was digested with PSA and many low molecular weight fragments were produced. When rEppin is bound to rSg, then digested by PSA, incomplete digestion and a 15-kDa fragment results. Antibody binding to the N-terminal of rEppin did not affect rSg digestion. Addition of antibodies to the C-terminal of rEppin inhibited the modulating effect of rEppin. Conclusion: Eppin protects a 15-kDa fragment of rSg from hydrolysis by PSA.

• 出版日期2008-9
• 单位南京医科大学