抗耐药金黄色葡萄球菌工程多肽—一种人工构建的抗菌蛋白质分子机器

Bactericidal Peptide Targeted Against Penicillin/Methicillinresistant Staphylococcus aureus──An Engineered Multidomain Protein Machine

目的 将两个不同种来源 ,不同生物活性的蛋白质结构域构建成为一种具有靶向抗菌活性的工程多肽。方法 利用质粒重组 ,将金黄色葡萄球菌 Agr D信息素 (8肽 )基因连接在大肠菌素 Ia水性孔道结构域 (K5 4 4 -I6 2 6 )羧基端基因上 ,将重组的质粒转化入工程菌生产构建的工程多肽 ,离子交换柱纯化后经体外抗菌试验检测其抗菌活性。结果 构建的工程多肽具有强于青霉素类抗生素上百倍的抗耐药金黄色葡萄球菌的活性。结论 构建的工程多肽表现出了两个结构域前体都不具备的靶向抗金黄色葡萄球菌活性 。

Objective To construct a targeting bactericidal peptide machine by fusing two minidomains with different bioactivities and different protein origins. Methods Such fusion peptide was constructed by linking the gene of Staphylococcal AgrD pheromone with the gene of C terminal (I626) of colicin Ia pore forming region(K544 I626) with site directed mutation. Mutated plasmid was transformed into E.coli TG1 cells to produce fusion peptide, peptides were purified by CM sepharose ion exchange column. in vitro bactericidal assays were made to identify the bioactivity of fusion peptide. Results Fusion peptide presented a specific bactericidal activity which was over one hundred times as effective as that of penicillin/oxacillin against tested Staphylococcus aureus strains. Conclusion Fusion peptide behaved with a targeting bactericidal activity against Staphylococcus aureus which was lacking at two precursors, Staphylococcal pheromone and colicin Ia pore forming region. These results suggest that an engineered multidomain protein machine with specific bactericidal activity has been constructed in the present study.