Identification and Characterization of Lactocyclicin Q, a Novel Cyclic Bacteriocin Produced by Lactococcus sp Strain QU 12
Identification and Characterization of Lactocyclicin Q, a Novel Cyclic Bacteriocin Produced by Lactococcus sp Strain QU 12
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DOI：
10.1128/aem.02299-08
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发表时间：
2009-03-01
影响因子：
4.4
通讯作者：
Sonomoto, Kenji
中科院分区：
文献类型：
--
作者：
Sawa, Naruhiko;Zendo, Takeshi;Sonomoto, Kenji
从干酪中分离得到乳球菌（Lactococcus sp.）菌株QU 12，通过阳离子交换色谱、疏水相互作用色谱、反相高效液相色谱等方法，从培养上清中分离得到乳环素Q，质谱测定其分子量为6062.8 Da。与其他已报道的乳酸菌素相比，乳环素Q具有独特的抗菌谱，高水平的蛋白酶抗性和热稳定性。通过化学方法确定了乳环素Q的氨基酸序列，该化合物由61个氨基酸残基组成，这些氨基酸残基具有环状结构，其N端和C端通过肽键连接。它与其他抗菌肽没有同源性，包括环细菌素。根据得到的氨基酸序列，得到了编码乳环素Q前肽的基因序列。这是第一份从乳球菌属菌株中纯化的环状细菌素的报告。
Lactococcus sp. strain QU 12, which was isolated from cheese, produced a novel cyclic bacteriocin termed lactocyclicin Q. By using cation-exchange chromatography, hydrophobic interaction chromatography, and reverse-phase high-performance liquid chromatography, lactocyclicin Q was purified from culture supernatant, and its molecular mass was determined to be 6,062.8 Da by mass spectrometry. Lactocyclicin Q has been characterized by its unique antimicrobial spectrum, high level of protease resistance, and heat stability compared to other reported bacteriocins of lactic acid bacteria. The amino acid sequence of lactocyclicin Q was determined chemically, and this compound is composed of 61 amino acid residues that have a cyclic structure with linkage between the N and C termini by a peptide bond. It showed no homology to any other antimicrobial peptide, including cyclic bacteriocins. On the basis of the amino acid sequences obtained, the sequence of the gene encoding the prepeptide lactocyclicin Q was obtained. This is the first report of a cyclic bacteriocin purified from a strain belonging to the genus Lactococcus.