The Arcanobacterium (Actinomyces) pyogenes hemolysin, pyolysin, is a novel member of the thiol-activated cytolysin family
The Arcanobacterium (Actinomyces) pyogenes hemolysin, pyolysin, is a novel member of the thiol-activated cytolysin family
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DOI：
10.1128/jb.179.19.6100-6106.1997
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发表时间：
1997-10-01
影响因子：
3.2
通讯作者：
Songer, JG
中科院分区：
文献类型：
--
作者：
Billington, SJ;Jost, BH;Songer, JG
化脓隐秘杆菌（Actinomycespyogenes）是一种动物病原菌，能产生溶血性外毒素--溶血素（pyolysin，PLO）。克隆了编码PLO的基因，序列分析表明其开放阅读框为1,605 bp，编码57.9 kDa的蛋白质。PLO与许多革兰氏阳性菌的巯基活化溶细胞素（TACY）有30 ~ 40%的同源性，其活性与其它TACY的同种糖非常相似，只是没有被巯基活化。特别是巯基活化所需的半胱氨酸残基已被丙氨酸取代，然而，丙氨酸残基突变为半胱氨酸并不赋予PLO巯基活化作用，提示该毒素的十一肽区存在构象差异。化脓性链球菌，这表明该微生物产生单一溶血素。此外，这些抗体可以被动地保护小鼠免受化脓性放线菌的致死性攻击，这表明PLO像其他TACY一样是该生物体发病机制中的重要毒力因子。
Arcanobacterium (Actinomyces) pyogenes, an animal pathogen, produces a hemolytic exotoxin, pyolysin (PLO), The gene encoding PLO was cloned, and sequence analysis revealed an open reading frame of 1,605 bp encoding a protein of 57.9 kDa. PLO has 30 to 40% identity with the thiol-activated cytolysins (TACYs) of a number of gram-positive bacteria, The activity of PLO was found to be very similar to allose of other TACYs, except that it was not thiol activated, The highly conserved TACY undecapeptide is divergent in PLO; in particular, the cysteine residue required for thiol activation has been replaced with alanine, However, mutagenesis of the alanine residue to cysteine did not confer thiol activation on PLO, suggesting a conformational difference in thf undecapeptide region of this toxin, Specific antibodies against purified, recombinant PLO completely neutralized the hemolytic activity of A. pyogenes, suggesting that this organism produces a single hemolysin. Furthermore, these antibodies could passively protect mice against lethal challenge with A, pyogenes, suggesting that like other TACYs PLO is an important virulence factor in the pathogenesis of this organism.