磷脂酶A_2氨基末端衍生肽的合成及其抗细菌活性的研究

Study on synthesis and antibacterial activity of phospholipase A_(2) amino-terminal derived peptide

目的 探讨磷脂酶A_(2)(PLA_(2))氨基末端衍生肽的合成及抗菌活性。方法 根据PLA_(2)氨基末端氨基酸残基的顺序合成为多肽PLA_(2)N_(11)、PLA_(2)N_(15)、PLA_(2)N_(20),将其分别与2种细菌(大肠埃希菌、枯草杆菌)在特定条件下培养,并以生理盐水作为对照,分析抗菌活性。结果 与对照比较,多肽不同作用浓度时PLA_(2)N_(11)、PLA_(2)N_(15)、PLA_(2)N_(20)对革兰氏阳性枯草杆菌杀菌活性更强,各多肽间比较,差异有统计学意义(P<0.05);当多肽作用浓度为500μg/ml时,PLA_(2)N_(15)对革兰氏阳性枯草杆菌杀菌活性可达99.8%,高于PLA_(2)N_(11)、PLA_(2)N_(20),及对照(P<0.05)。与对照比较,各多肽不同作用浓度时对大肠埃希菌杀菌活性比较,差异有统计学意义(P<0.05);多肽作用浓度为7.81、125.00、500.00μg/ml时,PLA_(2)N_(15)的杀菌活性均高于PLA_(2)N_(11)和PLA_(2)N_(20),及对照(P<0.05);多肽作用浓度为31.25μg/ml时,PLA_(2)N_(15)的杀菌活性低于PLA_(2)N_(11)的杀菌活性,且高于PLA_(2)N_(20)的杀菌活性(P<0.05)。结论 多肽PLA_(2)N_(11)、PLA_(2)N_(15)、PLA_(2)N_(20)对枯草杆菌、大肠埃希菌有很强的杀菌作用。

Objective To explore the synthesis and antibacterial activity of phospholipase A_(2)(PLA_(2))amino-terminal derived peptides.Methods Peptides PLA_(2)N_(11),PLA_(2)N_(15),and PLA_(2)N_(20) were synthesized based on the sequence of amino acid residues at the amino end of PLA_(2).They were cultured with two bacteria(Escherichia coli and Bacillus subtilis)under specific conditions,and saline was selected as control,the antibacterial activity was analyzed.Results Compared with the control,the polypeptide at different concentrations PLA_(2)N_(11),PLA_(2)N_(15),and PLA_(2)N_(20) had stronger bactericidal activity against G bacteria positive Bacillus subtilis,and the difference among peptides was statistically significant(P<0.05).When the polypeptide concentration was 500μg/ml,the bactericidal activity of PLA_(2)N_(15) against G bacteria positive Bacillus subtilis was 99.8%higher than that of PLA_(2)N_(11) and PLA_(2)N_(20),and control(P<0.05).Compared with the control,there was statistical significance in the bactericidal activity against Escherichia coli at different concentrations(P<0.05).The bactericidal activity of PLA_(2)N_(15) was higher than that of PLA_(2)N_(11),PLA_(2)N_(20),and control at peptide concentrations of 7.81,125.00,and 500.00μg/ml(P<0.05).The bactericidal activity of PLA_(2)N_(15) was lower than that of PLA_(2)N_(11) and higher than that of PLA_(2)N_(20) at 31.25μg/ml polypeptide concentration(P<0.05).Conclusion Peptides PLA_(2)N_(11),PLA_(2)N_(15),and PLA_(2)N_(20) have strong bactericidal effects on Bacillus subtilis and Escherichia coli.