Isolation of human cationic antimicrobial protein-18 from seminal plasma and its association with prostasomes
Isolation of human cationic antimicrobial protein-18 from seminal plasma and its association with prostasomes
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DOI：
10.1093/humrep/17.10.2529
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发表时间：
2002-10-01
影响因子：
6.1
通讯作者：
Malm, J
中科院分区：
文献类型：
--
作者：
Anderson, E;Sorensen, OE;Malm, J
背景：Cathelicidins是一类具有广泛抗菌活性的抗菌肽。它们被认为是先天免疫系统的重要组成部分。唯一已知的人凯萨林菌素是人阳离子抗微生物蛋白（hCAP-18），从中释放出抗微生物肽LL-37。方法和结果：在本研究中，我们从精浆中纯化了hCAP-18，并通过N-末端氨基酸测序证实了其身份。精浆的凝胶过滤显示hCAP-18在低和高分子量峰中的存在。对应于hCAP-18的高分子形式的级分还含有二肽基肽酶IV（CD 26），一种前列腺酶体标记物。这一发现表明，在对应于高分子量分子的级分中发现的hCAP-18是前列腺酶体相关的。流式细胞术证实了hCAP-18与前列腺体的缔合，并表明该分子是表面结合的。Western blot显示精子、前列腺体和超浓缩精浆中存在完整的hCAP-18。结论：这些发现表明，hCAP-18可能在人类生殖过程中的抗菌防御中发挥重要作用。hCAP-18与前列腺酶体的结合表明，前列腺酶体可以作为抗生素肽LL-37的这种前体的储存库。
BACKGROUND: Cathelicidins are a group of antibiotic peptides with broad antimicrobial activity. They are considered to be an essential part of the innate immune system. The only known human cathelicidin is the human cationic antimicrobial protein (hCAP-18), from which the antimicrobial peptide LL-37 is released. METHODS AND RESULTS: In the present study, we purified hCAP-18 from seminal plasma and confirmed its identity by N-terminal amino acid sequencing. Gel filtration of seminal plasma showed the presence of hCAP-18 in both a low and a high molecular weight peak. Fractions corresponding to the high molecular form of hCAP-18 also contained dipeptidyl peptidase IV (CD26), a prostasome marker. This finding suggested that hCAP-18 found in fractions corresponding to high molecular weight molecules, is prostasome-associated. Flow cytometry confirmed the association of hCAP-18 with prostasomes and indicated that the molecule is surface bound. Western blot showed the presence of intact hCAP-18 in sperm, prostasomes and ultracentrifuged seminal plasma. CONCLUSIONS: These findings suggest that hCAP-18 may have an important role in antimicrobial defence during human reproduction. The binding of hCAP-18 to prostasomes indicates that protasomes can serve as a reservoir of this precursor of the antibiotic peptide LL-37.