人Ⅰ型磷脂酶A_2的N末端衍生多肽PLA_2N_(1-15)的杀菌活性研究

目的:观察人Ⅰ型磷脂酶A2(PLA2)的N末端衍生多肽PLA2N1-15对不同细菌的体外杀菌活性。方法:以人Ⅰ型PLA2N末端的15个氨基酸残基为模板,合成多肽PLA2N1-15。采用琼脂铺板计数法,记录并计算不同质量浓度(1 000、250、62.5、15.625μg/ml)的PLA2N1-15对革兰阳性(G+)菌(金黄色葡萄球菌、粪肠球菌、枯草芽孢杆菌)和革兰阴性(G-)菌(大肠埃希菌、铜绿假单胞菌、变形杆菌)的杀菌率。结果:15.625、62.5、250、1 000μg/ml的PLA2N1-15对G+菌的杀菌率分别为10%¹9%、36.55%19%、36.55%⁸9.73%、83%89.73%、83%¹00%、96%100%、96%¹00%,对G-菌的杀菌率分别为8.86%100%,对G-菌的杀菌率分别为8.86%²2.63%、21.61%22.63%、21.61%⁴0.55%、40%40.55%、40%⁸3%、87%83%、87%⁹3%。结论:高浓度PLA2N1-15对G+和G-均具有较强的杀菌活性,特别是对G+。

Study on Bactericidal Activity of the Polypeptide Derived from N-terminal Sequence of Human Group I Phospholipase A2

OBJECTIVE： To observe the bactericidal activity of the polypeptide derived from N-terminal sequence of human type I phospholipase A2 （PLA1N1-15） in vitro. METHODS： PLA2N1-15 was synthesized according to 15 amino acid sequence from N-terminal of human type I PLA2. The sterilizing rate of different concentrations of PLA2N1-15 （1 000, 250, 62.5, 15.625 μg/ml） to Gram-positive bacteria （including Staphylococcus aureus, Enterococcus faecalis, Bacillus subtilis） and Gram-negative bacteria （including Escherichia coli, Pseudomonas aeruginosa, Proteusbacillus vulgaris） were calculated and recorded by agar plate colony counting. RESULTS： The sterilizing rates of 15.625, 62.5, 250 and 1 000 μg/ml PLA2N1-15 to Gram-positive bacteria were 10%- 19%, 36.55%-89.73%, 83%-100% and 96%-100%, respectively; those to Gram-negative bacteria were 8.86%-22.63%, 21.61%- 40.55 %, 40 % -83 % and 87 %-93 %, respectively. CONCLUSIONS： High concentration of PLA2N1-15 possesses strong bactericidal activity to Gram-positive bacteria and Gram-negative bacteria, particular to Gram-positive bacteria.