Hu C-B, Zendo T, Nakayama J, Sonomoto K
Laboratory of Microbial Technology, Division of Microbial Science and Technology, Department of Bioscience and Biotechnology, Faculty of Agriculture, Graduate School, Kyushu University, Higashi-ku, Fukuoka, Japan.
J Appl Microbiol. 2008 Sep;105(3):681-90. doi: 10.1111/j.1365-2672.2008.03798.x. Epub 2008 Apr 5.
To characterize the novel bacteriocin produced by Enterococcus durans.
Enterococcus durans QU 49 was isolated from carrot and expressed bactericidal activity over 20-43 degrees C. Bacteriocins were purified to homogeneity using the three-step purification method, one of which, termed durancin TW-49M, was an enterocin B-homologous peptide with most identical residues occurring in the N-terminus. Durancin TW-49M was more tolerant in acidic than in alkali. DNA sequencing analysis revealed durancin TW-49M was translated as a prepeptide of the double-glycine type. Durancin TW-49M and enterocin B expressed similar antimicrobial spectra, in which no significant variation due to the diversity in their C-termini was observed.
Durancin TW-49M, a novel nonpediocin-like class II bacteriocin, was characterized to the amino acid and genetic levels. The diverse C-terminal parts of durancin TW-49M and enterocin B were hardly to be suggested as the place determining the target cell specificity.
This is the first and comprehensive study of a novel bacteriocin produced by Ent. durans. The high homology at the N-terminal halves between durancin TW-49M and enterocin B makes them suitable to study the structure-function relationship of bacteriocins and their immunity proteins.
对耐久肠球菌产生的新型细菌素进行特性分析。
从胡萝卜中分离出耐久肠球菌QU 49，其在20至43摄氏度具有杀菌活性。采用三步纯化法将细菌素纯化至同质，其中一种名为耐久菌素TW - 49M的细菌素是一种与肠球菌素B同源的肽，大多数相同残基出现在N端。耐久菌素TW - 49M在酸性条件下比在碱性条件下更具耐受性。DNA测序分析表明，耐久菌素TW - 49M被翻译为双甘氨酸型前肽。耐久菌素TW - 49M和肠球菌素B表现出相似的抗菌谱，未观察到因其C端差异而导致的显著变化。
耐久菌素TW - 49M是一种新型的非片球菌素样II类细菌素，已在氨基酸和基因水平上进行了特性分析。耐久菌素TW - 49M和肠球菌素B不同的C端部分很难被认为是决定靶细胞特异性的部位。
这是对耐久肠球菌产生的新型细菌素的首次全面研究。耐久菌素TW - 49M和肠球菌素B在N端一半的高度同源性使其适合用于研究细菌素及其免疫蛋白的结构 - 功能关系。
