穿透肽嵌合金黄色葡萄球菌噬菌体裂解酶LysJS25-R9的表达及其活性分析

Expression and antibacterial activity of lysin LysJS25-R9 of cell penetrating peptide chimeric S. aureus phage lysin

前期分离得到1株具有较强裂解能力的金黄色葡萄球菌噬菌体vB_SauM_JS25。测序后发现,噬菌体vB_SauM_JS25的裂解酶基因LysJS25与裂解酶LysK同源性最高,且可以广谱裂解金黄色葡萄球菌。为提高LysJS25细胞穿透效果,设计了穿透肽嵌合裂解酶LysJS25-R9,经原核表达和纯化,体外评价了LysJS25-R9裂解活性、细胞穿透活性及细胞内杀菌活性。结果表明:LysJS25-R9对葡萄球菌表现出较好的裂解能力,杀菌效率较原裂解酶提高2.1倍。激光共聚焦及细胞内杀菌活性实验证实LysJS25-R9进入MAC-T细胞内杀菌。该研究为穿透肽嵌合裂解酶的设计提供了一个良好的例证,同时有助于裂解酶细胞穿透性改造的设计。

A strain of S. aureus phage vBSauMJS25 with good lysis ability was isolated in previous experiments. We found that the phage LysJS25 gene of vBSauMJS25 showed highly homologous with LysK, and also a broad spectrum of lysis ability against S. aureus. To improve the cell penetrating efficiency of LysJS25, we designed a cell penetrating peptide chimeric S. aureus phage lysin. To explore the lysis activity of chimeric lysin, LysJS25 was expressed in prokaryotic cells and purified. The lysis activity and the cell penetrating activity of LysJS25-R9 were determined. Our results showed that the lysis activity against S. aureus of LysJS25-R9 was 2.1 times higher than LysJS25. The laser confocal and intracellular lysis activity assay also showed that LysJS25-R9 could penetrate bovine mammary epithelial cells to kill intracellular S. aureus. These results not only provide strong evidence for the study cell penetrating peptide chimeric phage lysin, but also contribute to the design of cell penetrating peptide chimeric lysin.