Many-body effect of antimicrobial peptides: On the correlation between lipid's spontaneous curvature and pore formation
Many-body effect of antimicrobial peptides: On the correlation between lipid's spontaneous curvature and pore formation
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DOI：
10.1529/biophysj.105.068080
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发表时间：
2005-12-01
影响因子：
3.4
通讯作者：
Huang, HW
中科院分区：
文献类型：
--
作者：
Lee, MT;Hung, WC;Huang, HW
最近，我们已经表明，由抗菌肽诱导的孔形成的自由能包含一个术语，代表膜变薄介导的肽-肽相互作用。这种多体效应引起肽活性的协同浓度依赖性。在这里，我们进行了定向圆二色性和X射线衍射实验，以研究这种多体效应的脂质依赖性。特别是，我们研究了脂质的自发曲率和肽的阈值浓度之间的相关性，通过加入磷脂酰乙醇胺和溶血磷酸胆碱的磷酸胆碱双分子层的孔形成。以前有人认为，这种相关性表现出爪蟾抗菌肽和蜂毒肽支持的环形模型的孔。在这里，我们发现蜂毒肽和丙甲霉素表现出类似的相关性。我们发现，改变脂质的自发曲率的主要影响是改变膜变薄的程度，这反过来又影响孔形成的阈值浓度。我们讨论如何解释膜变薄的脂质依赖性。
Recently we have shown that the free energy for pore formation induced by antimicrobial peptides contains a term representing peptide-peptide interactions mediated by membrane thinning. This many-body effect gives rise to the cooperative concentration dependence of peptide activities. Here we performed oriented circular dichroism and x-ray diffraction experiments to study the lipid dependence of this many-body effect. In particular we studied the correlation between lipid's spontaneous curvature and peptide's threshold concentration for pore formation by adding phosphatidylethanolamine and lysophosphocholine to phosphocholine bilayers. Previously it was argued that this correlation exhibited by magainin and melittin supported the toroidal model for the pores. Here we found similar correlations exhibited by melittin and alamethicin. We found that the main effect of varying the spontaneous curvature of lipid is to change the degree of membrane thinning, which in turn influences the threshold concentration for pore formation. We discuss how to interpret the lipid dependence of membrane thinning.