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目的观察衍生自人ⅡA型磷脂酶A2(PLA2)N-端的多肽hPLA2N1-11对不同细菌在体外的杀菌效应。方法根据人ⅡA型PLA2N-端11个氨基酸残基的顺序,合成hPLA2N1-11。将不同浓度的多肽分别与革兰阳性菌和革兰阴性菌在温度为37℃中水浴2 h,取出铺板,置于37℃培养18～24 h,取出并记录每块琼脂板的菌落生成数(CFU),计算杀菌率。结果 hPLA2N1-11对同属革兰阳性(G+)菌的金黄色葡萄球菌、枯草杆菌、炭疽杆菌的杀菌作用较强;对同属革兰阴性(G-)菌的大肠杆菌、变形杆菌和绿脓杆菌的杀菌作用较弱,人ⅡA型PLA2衍生肽虽然只有原分子1/10的大小,但仍具有与ⅡA型PLA2类似的杀菌效应。结论多肽hPLA2N1-11对革兰阳性菌杀菌作用强,对革兰阴性菌杀菌作用弱,可能具有与ⅡA型PLA2类似的杀菌机制。
Objective To observe the in vitro bactericidal effect of hPLA2N1-11 derived from the N-terminal of human type Ⅱ A phospholipase A2 (PLA2) on different bacteria. Methods The hPLA2N1-11 was synthesized according to the sequence of 11 amino acid residues of human Ⅱ A PLA2 N-terminal. The different concentrations of peptides were respectively incubated with Gram-positive bacteria and Gram-negative bacteria at a temperature of 37 ℃ for 2 h, and the plates were removed and incubated at 37 ° C for 18-24 h. The number of colonies per agar plate was taken out and recorded (CFU), calculate the sterilization rate. Results The bactericidal effect of hPLA2N1-11 against Staphylococcus aureus, Bacillus subtilis and Bacillus anthracis of Gram-positive bacteria (G +) was strong. Escherichia coli, Proteus and Pseudomonas aeruginosa belonging to the same gram- Bactericidal effect is weaker. Human ⅡA PLA2-derived peptide has the same bactericidal effect as type ⅡA PLA2 though it only has the size of original molecule 1/10. Conclusion The polypeptide hPLA2N1-11 has strong bactericidal activity against Gram-positive bacteria and weak bactericidal activity against Gram-negative bacteria, which may be similar to PLA2.