摘要
目的比较人ⅡA型磷脂酶A2(phospholipase A2,PLA2)C末端衍生的多肽和经修饰后的环肽对不同细菌在体外的杀菌效应,了解其作用机制。方法根据人ⅡA型PLA2氨基酸顺序C末端26个氨基酸残基,合成直链肽P26,同时将其修饰为环肽P26。采用琼脂铺板计数法,将不同浓度的两种多肽分别与6种细菌在37℃孵育2 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。结果两种多肽对革兰阳性菌金黄色葡萄球菌、枯草杆菌和炭疽杆菌有较强的杀菌活性,环肽P26的作用比直链肽P26强4倍左右;对革兰阴性菌大肠杆菌、变形杆菌和绿脓杆菌的杀菌作用较弱,而环肽P26的作用更弱。结论衍生自人ⅡA型PLA2 C末端26个氨基酸残基的肽P26和修饰得到的环肽P26对G+菌有较强的杀菌活性,经修饰成环肽后作用更强,可能与环肽分子带的正电荷更集中有关。
Aim To study the bactericidal activity and structure modification of the polypeptide P26 which de- rives from C-terminal 26 amino acid residues of Human Group 11 A phospholipase Az （Group IIA PLAz ） in vitro, and to understand the mechanism of bactericidal activity for the two derived peptides. Methods Linear polypeptide P26 was synthesized acorrding to the C-ter- minal 26 amino acid residues sequence of Human Group 11 A phospholipase A2, and some of them weretire （ G ＋ ） bacteria , such as Staphylococcus aureus, Bacillus subtilis, Bacillus anthrax; but weak bactericid- al activity on the gram-negative （G-） bacteria, such as Escherichia coli, Bacillus proteus, Bacillus pyocya- neus. The bactericidal activity of the cyclic polypeptide was abou 4 times higher than linear polypeptide P＇26 on the G ~ bacteria, but it was not for the G- bacteria. Conclusions The two peptides which derive from C- terminal 26 amino acid residues of Human Group 11 Amodified to be a cyclic polypeptide P26 . 6 species of bacterial solution with different concentration of poly- peptide were incubated at 37~C for 2 hours in a water bath respectively. Then the reaction solution was dilu- ted and agar plates were poured. After 18 ~ 24 hours, incubation in the thermostated container at 37~C, the colony formed unit was counted and the ＇bactericidal rates were calculated. Results The two polypeptides possessed potent bactericidal activity on the gram - posi-phospholipase A2 possess potent bactericidal activity a- gainst G ＋ bacteria. The activity of cylic P26 is higher than linear P26 on G ~ bacteria. It more concentrated charged residues may be due to in cyclic P26.
出处
《中国药理学通报》
CAS
CSCD
北大核心
2011年第9期1300-1304,共5页
Chinese Pharmacological Bulletin
基金
广西自然科学基金资助项目(No2010GXNSFA013246)
广西卫生厅重点资助项目(No重200707)
关键词
人ⅡA型磷脂酶A2
C末端
抗菌肽
直链肽
环肽
抗菌活性
结构修饰
Human Group U A phospholipase A2
C-terminal
antibacterial peptide
linear polypeptide
cy-clic polypeptide
bactericidal activity
structure modifi-cation.
