Thermophilin 13, a nontypical antilisterial poration complex bacteriocin, that functions without a receptor
Thermophilin 13, a nontypical antilisterial poration complex bacteriocin, that functions without a receptor
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DOI：
10.1074/jbc.272.22.14277
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发表时间：
1997-05-30
影响因子：
4.8
通讯作者：
Poolman, B
中科院分区：
文献类型：
--
作者：
Marciset, O;JeronimusStratingh, MC;Poolman, B
从嗜热链球菌的生长培养基中分离并纯化出一种新型的广泛宿主范围的抗菌物质，嗜热蛋白 13。 Thermophilin 13由抗菌肽ThmA（M-r为5776）和增强因子ThmB（M-r为3910）组成；后一种肽使 ThmA 的活性增加了约 40 倍，两种肽均由单个操纵子编码，等摩尔比对于嗜热菌素 13 活性是最佳的，尽管嗜热菌素 13 具有抗李斯特菌活性，但 ThmA 和 ThmB 均不包含李斯特菌活性肽的 YGNGV-C 共有序列，并且也不存在与羊毛硫抗生素中相当的翻译后修饰，Mass 光谱分析确实揭示了 ThmA 中蛋氨酸的明显氧化，这导致肽不能再被 ThmB 增强，而内在的杀菌活性是正常的，嗜热蛋白 13 消散了脂质体中的膜电位和 pH 梯度，并且这种活性与敏感菌株的膜成分（例如脂质或蛋白质受体）无关。 基于嗜热蛋白 13 的序列比较、结构预测和功能分析，提出了形成的孔化复合物。
A novel broad host range antimicrobial substance, Thermophilin 13, has been isolated and purified from the growth medium of Streptococcus thermophilus. Thermophilin 13 is composed of the antibacterial peptide ThmA (M-r of 5776) and the enhancing factor ThmB (M-r of 3910); the latter peptide increased the activity of ThmA similar to 40 x, Both peptides are encoded by a single operon, and an equimolar ratio was optimal for Thermophilin 13 activity, Despite the antilisterial activity of Thermophilin 13, neither ThmA nor ThmB contain the YGNGV-C consensus sequence of Listeria active peptides, and post-translational modifications comparable to that in the lantibiotics are also absent, Mass spectrometry did reveal the apparent oxidation of methionines in ThmA, which resulted in a peptide that could not be enhanced any longer by ThmB, whereas the intrinsic bactericidal activity was normal, Thermophilin 13 dissipated the membrane potential and the pH gradient in liposomes, and this activity was independent of membrane components from a sensitive strain (e.g. lipid or proteinaceous receptor), Models of possible poration complexes formed are proposed on the basis of sequence comparisons, structure predictions, and the functional analysis of Thermophilin 13.