Semenogelin I (SgI) is one of the most abundant proteins in human seminal plasma. SgI plays a key role in sperm coagulation and spermatozoon immobilization. in addition, SgI and/or its proteolytic fragments are involved in regulating spermatozoon motility, capacitation and inhibin-like activity. However, little is known about the antibacterial activity of SgI-derived peptides. By a combination of ion-exchange, gel filtration and high-performance liquid chromatography, peptides from liquefied human seminal plasma from 40 healthy donors were isolated and characterized. N-terminal amino-acid sequencing and fast atom bombardment mass spectrometry revealed that four isolated peptides were SgI-derived, namely SgI-29 (8S-113), SgI-46 (85-130), SgI-47 (85-131) and SgI-52 (85-136). Interestingly, SgI-29, SgI-46 and SgI-47 are newly identified SgI-derived peptides. Antimicrobial activity assay results indicated that synthesized SgI-29 had strong antibacterial activity toward various bacterial strains. Our results indicate that SgI can be digested into small fragments like newly identified SgI-29, SgI-46 and SgI-47 and may have diversified functions. (C) 2008 Elsevier Inc. All rights reserved.
[1]Sichuan Univ, Dept Urol, W China Hosp, Chengdu 610041, Peoples R China.
[2]Chinese Acad Sci, Kunming Inst Zool, Key Lab Anim Models & Human Dis Mech, Biotoxin Units, Kunming 650223, Yunnan, Peoples R China.
[3]First Affiliated Hosp Kunming Med Coll, Dept Urol, Kunming 650032, Yunnan, Peoples R China.
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