Department of Food and Animal Biotechnology, Department of Agricultural Biotechnology, Center for Agricultural Biomaterials, and Research Institute for Agriculture and Life Sciences, Seoul National University, Seoul 151-921, Republic of Korea.
Res Microbiol. 2012 Apr;163(3):233-41. doi: 10.1016/j.resmic.2012.01.002. Epub 2012 Jan 18.
The full genome sequence of bacteriophage SPN1S, which infects Salmonella, contains genes that encode homologues of holin, endolysin and Rz/Rz1-like accessory proteins, which are 4 phage lysis proteins. The ability of these proteins to lyse Escherichia coli cells when overexpressed was evaluated. In contrast to other endolysins, the expression of endolysin and Rz/Rz1-like proteins was sufficient to cause lysis. The endolysin was tagged with oligohistidine at the N-terminus and purified by affinity chromatography. The endolysin has a lysozyme-like superfamily domain, and its activity was much stronger than that of lysozyme from chicken egg white. We used the chelating agent, ethylenediaminetetraacetic acid (EDTA), to increase outer membrane permeability, and it greatly enhanced the lytic activity of SPN1S endolysin. The antimicrobial activity of endolysin was stable over broad pH and temperature ranges and was active from pH 7.0 to 10.5 and from 25 °C to 45 °C. The SPN1S endolysin could kill most of the tested Gram-negative strains, but the Gram-positive strains were resistant. SPN1S endolysin, like lysozyme, cleaves the glycosidic bond of peptidoglycan. These results suggested that SPN1S endolysin has potential as a therapeutic agent against Gram-negative bacteria.
噬菌体 SPN1S 的全基因组序列，该噬菌体感染沙门氏菌，包含编码溶菌酶、内切酶和 Rz/Rz1 样辅助蛋白同源物的基因，这些都是 4 种噬菌体裂解蛋白。评估了这些蛋白在过表达时裂解大肠杆菌细胞的能力。与其他内切酶不同，表达内切酶和 Rz/Rz1 样蛋白足以导致裂解。内切酶在 N 端带有寡组氨酸标签，并通过亲和层析进行纯化。内切酶具有溶菌酶样超家族结构域，其活性比鸡卵清溶菌酶强得多。我们使用螯合剂乙二胺四乙酸（EDTA）来增加外膜通透性，这大大增强了 SPN1S 内切酶的裂解活性。内切酶的抗菌活性在较宽的 pH 和温度范围内稳定，在 pH 7.0 到 10.5 和 25°C 到 45°C 之间均具有活性。SPN1S 内切酶可以杀死大多数测试的革兰氏阴性菌，但革兰氏阳性菌具有抗性。SPN1S 内切酶与溶菌酶一样，可切割肽聚糖的糖苷键。这些结果表明，SPN1S 内切酶具有作为治疗革兰氏阴性菌的潜在用途。
