Tyumen State University, Volodarsky st, 6, Tyumen, Russian Federation, 625003.
Institute of Cellular and Intracellular Symbiosis, RAS, Pionerskaya st, 11, Orenburg, Russian Federation, 460000.
Probiotics Antimicrob Proteins. 2018 Sep;10(3):427-434. doi: 10.1007/s12602-018-9392-0.
Discovery of a novel bacteriocin is always an event in sciences, since cultivation of most bacterial species is a general problem in microbiology. This statement is reflected by the fact that number of bacteriocins is smaller for tenfold comparing to known antimicrobial peptides. We cultivated Enterococcus faecium on simplified medium to reduce amount of purification steps. This approach allows to purify the novel heavy weight bacteriocin produced by E. faecium ICIS 7. The novelty of this bacteriocin, named enterocin-7, was confirmed by N-terminal sequencing and by comparing the structural-functional properties with available data. Purified enterocin-7 is characterized by a sequence of amino acid residues having no homology in UniProt/SwissProt/TrEMBL databases: NH2 - Asp - Ala - His - Leu - Ser - Glu - Val - Ala - Glu - Arg - Phe - Glu - Asp - Leu - Gly. Isolated thermostable protein has a molecular mass of 65 kDa, which allows it to be classified into class III in bacteriocin classification schemes. Enterocin-7 displayed a broad spectrum of activity against some Gram-positive and Gram-negative microorganisms. Fluorescent microscopy and spectroscopy showed the permeabilizing mechanism of the action of enterocin-7, which is realized within a few minutes.
发现新型细菌素一直是科学界的一件大事，因为培养大多数细菌物种是微生物学中的一个普遍问题。这一说法反映了一个事实，即与已知的抗菌肽相比，细菌素的数量要少十倍。我们在简化培养基上培养屎肠球菌，以减少纯化步骤的数量。这种方法允许纯化由屎肠球菌 ICIS 7 产生的新型重链细菌素。这种新型细菌素，命名为肠菌素-7，通过 N 端测序和比较结构-功能特性与现有数据得到证实。纯化的肠菌素-7的特征是具有氨基酸残基序列，在 UniProt/SwissProt/TrEMBL 数据库中没有同源性：NH2 - 天冬氨酸 - 丙氨酸 - 组氨酸 - 亮氨酸 - 丝氨酸 - 谷氨酸 - 缬氨酸 - 丙氨酸 - 谷氨酸 - 精氨酸 - 苯丙氨酸 - 谷氨酸 - 天冬氨酸 - 亮氨酸 - 甘氨酸。分离出的热稳定蛋白的分子量为 65 kDa，这使其能够在细菌素分类方案中归类为 III 类。肠菌素-7对一些革兰氏阳性和革兰氏阴性微生物表现出广谱的活性。荧光显微镜和光谱学显示了肠菌素-7的作用的通透机制，这在几分钟内就实现了。
