Lethal hydroxyl radical accumulation by a lactococcal bacteriocin, lacticin Q.
Lethal hydroxyl radical accumulation by a lactococcal bacteriocin, lacticin Q.
复制标题
乳球菌细菌素、乳酸 Q 导致致命的羟基自由基积累。
DOI：
10.1128/aac.00638-13
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发表时间：
2013
期刊：
影响因子：
--
通讯作者：
Sonomoto K
中科院分区：
文献类型：
--
作者：
Li M;Yoneyama F;Toshimitsu N;Zendo T;Nakayama J;Sonomoto K
乳酸菌素Q是一种乳球菌细菌素，其抗菌机理可用无受体的环形孔模型来描述。然而，乳酸菌素Q显示出不同程度的活性（选择性抗微生物活性）对革兰氏阳性菌，甚至在相关的物种。乳酸菌素Q诱导不同指示菌株脂质组成的脂质体中孔形成的能力表明，其选择性抗菌活性不能仅归因于膜脂质组合物。我们研究了暴露于乳酸菌素Q后有害羟基自由基的积累作为指示菌株中细胞死亡的一个促成因素。当将与MIC或最低杀菌浓度相同浓度的乳酸菌素Q加入指示培养物中时，检测到高水平的羟基自由基积累。用羟基自由基清除剂硫脲和2，2 ′-联吡啶处理，降低了羟基自由基的积累水平，恢复了细胞活力。这些结果表明，有或没有孔形成，乳酸菌素Q的最终抗菌机制是羟基自由基的积累，这因菌株而异，导致乳酸菌素Q的选择性抗菌活性。
The antimicrobial mechanism of a lactococcal bacteriocin, lacticin Q, can be described by the toroidal pore model without any receptor. However, lacticin Q showed different degrees of activity (selective antimicrobial activity) against Gram-positive bacteria even among related species. The ability of lacticin Q to induce pore formation in liposomes composed of lipids from different indicator strains indicated that its selective antimicrobial activity could not be attributed only to membrane lipid composition. We investigated the accumulation of deleterious hydroxyl radicals after exposure to lacticin Q as a contributing factor to cell death in the indicator strains. When lacticin Q of the same concentration as the MIC or minimum bactericidal concentration was added to the indicator cultures, high levels of hydroxyl radical accumulation were detected. Treatment with hydroxyl radical scavengers, thiourea and 2,2′-bipyridyl, decreased the levels of hydroxyl radical accumulation and recovered cell viability. These results suggest that, with or without pore formation, the final antimicrobial mechanism of lacticin Q is the accumulation of hydroxyl radicals, which varies by strain, resulting in the selective antimicrobial activity of lacticin Q.