摘要
目的研究人ⅡA型磷脂酶A2(PLA2) N端15肽及其衍生肽的杀菌活性。方法以人ⅡA型PLA2一级结构N末端的15个氨基酸残基为模板,分别合成结构不同的多肽,包括PLA2-N15、PLA2-H6R、PLA2-H6R-T12R、PLA2-H6R-T12V、PLA2-N4R-H6R、PLA2-N4R-H6R-T13R、PLA2-N1A-H6R-T12L。采用琼脂铺板计数法,记录并计算不同浓度(8、40、200、1 000μg/ml)的多肽对革兰阳性菌(金黄色葡萄球菌)和革兰阴性菌(大肠埃希菌)的杀菌率。结果多肽浓度为200μg/ml和1 000μg/ml时,6种衍生肽对革兰阳性菌的杀菌率均高于PLA2-N15(均P <0. 05);任一浓度下PLA2-H6R-T12V与PLA2-N1A-H6R-T12L对革兰阳性菌的杀菌率均高于其他4种衍生肽(均P <0. 05)。多肽浓度为200μg/ml和1 000μg/ml时,除PLA2-H6R外,其他5种衍生肽对革兰阴性菌的杀菌率均高于PLA2-N15(均P <0. 05),且PLA2-H6R-T12V与PLA2-N1A-H6R-T12L对革兰阴性菌的杀菌率均高于其他4种衍生肽(均P <0. 05)。结论人ⅡA型PLA2N端衍生肽的杀菌活性与疏水性氨基酸比例和位置密切相关,将衍生肽第12位氨基酸替换为疏水性氨基酸时杀菌活性最强,在多肽分子结构中的某些位置增加碱性氨基酸亦有助于增强其杀菌活性。
Objective To study the bactericidal activity of human groupⅡA phospholipase A2( PLA2) N-terminal15 peptide and its derivative peptide. Methods Using 15 amino acid residues in N-terminal primary structure of human group ⅡA PLA2 as the templates,polypeptides with different structures were synthesized separately,including PLA2-N15,PLA2-H6 R,PLA2-H6 R-T12 R,PLA2-H6 R-T12 V,PLA2-N4 R-H6 R,PLA2-N4 R-H6 R-T13 R,PLA2-N1 A-H6 R-T12 L. Agar plate counting assay was used to record and calculate the bactericidal activity of polypeptides at various concentrations( 8,40,200,1 000 μg/ml) against Gram-positive bacteria( Staphylococcus aureus) and Gram-negative bacteria( Escherichia coli). Results At concentrations of 200 and 1 000 μg/ml of polypeptide,six derivative peptides obtained a higher bactericidal activity against Gram-positive bacteria compared with PLA2-N15( all P < 0. 05);PLA2-H6 R-T12 V or PLA2-N1 A-H6 R-T12 L at any concentration had a higher bactericidal activity against Gram-positive bacteria compared with the other four derivative peptides( all P < 0. 05). At concentrations of 200 and 1 000 μg/ml of polypeptide,except PLA2-H6 R,the other five derivative peptides exhibited a higher bactericidal activity against Gram-negative bacteria in contrast to PLA2-N15( all P < 0. 05),and the bactericidal activity of PLA2-H6 R-T12 V or PLA2-N1 A-H6 R-T12 L was higher than that of the other four derivative peptides( all P < 0. 05). Conclusion Human group ⅡA PLA2 N-terminal derivative peptide has a bactericidal activity closely related to the ratio and position of hydrophobic amino acid,the strongest bactericidal activity is noted when derivative peptide 12 th amino acid is replaced with hydrophobic amino acid,additional basic amino acid applied to certain positions in the molecular structure of polypeptide might contribute to enhancing its bactericidal activity.
作者
郭娟
李永杰
梁宁生
GUO Juan;LI Yong-jie;LIANG Ning-sheng(Department of Pharmacy,Guangxi Medical University Affiliated Tumor Hospital,Nanning 530021,China)
出处
《广西医学》
CAS
2019年第6期729-733,共5页
Guangxi Medical Journal
基金
广西自然科学基金(2013GXNSFAA019250)
关键词
人ⅡA型磷脂酶A2
N末端
衍生肽
分子结构
杀菌活性
Human groupⅡA phospholipase A2
N-terminal
Derivative peptide
Molecular structure
Bactericidal activity
