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目的研究和比较人ⅡA型磷脂酶A2(phospholipase A2，PLA2)衍生多肽CT17对不同细菌在体外的杀菌效应。方法根据人ⅡA型PLA2氨基酸顺序分别设计合成肽分子CT17（p51-67）。采用琼脂铺板计数法测定杀菌活性，将不同浓度衍生肽分别与革兰氏阳性菌（G+）金黄色葡萄球菌、枯草杆菌、屎肠球菌和革兰氏阴性菌(G-)大肠杆菌、绿脓杆菌、鲍曼不动杆菌在37℃孵育2.5 h，然后铺板并置于37℃恒温箱培养18～24 h，记录每一琼脂板上的菌落数(CFU)，并计算多肽作用后的杀菌率。结果 IA型PLA2CT17对G+菌与G-菌均有较强的杀菌活性。结论衍生自人ⅡA型PLA2保守区域17个氨基酸残基的肽M17对G+菌和G-均有较强的杀菌活性，这可能与M17肽分子更易于与细菌结合并发挥作用有关。“,” Object To study and compare the bactericidal activity of the polypeptide CT17 which derives from human Group ⅡA phospholipase A2 (PLA2, phospholipase A2) in vitro. Methods Peptide CT17(p51-67) was synthesized according to the sequence of human GroupⅡA PLA2 amino acid. Six species of bacterial, Gram positive(G+) Staphy 1ococcus aureus , Bacilus subtilis , Enterococcus faecium , Gram negative(G-) Escherichia coli , Acinetobacter baumanni , Bacilus pyocyaneus , were incubated with different concentration of polypeptides at 37℃for 2.5 hours in a water bath respectively. Then the reaction solution was diluted and agar plates were poured. After 18-24 hours incubation in the thermostated container at 37℃.The colony formed units were counted and the bactericida1 rates were calculated. Results PLA2CT17 possessed potent bactericidal activity on the G+ bacteria and G-bacteria. Conclusions: Peptide CT17 derived from human Ⅱ type A PLA2 highly conserve region possesses a strong bactericidal activity, this may be related to the CT7 peptide molecules more easily binding to bacteria.