Membrane thinning caused by magainin 2
Membrane thinning caused by magainin 2
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DOI：
10.1021/bi00051a026
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发表时间：
1995-12-26
期刊：
影响因子：
2.9
通讯作者：
Huang, H
中科院分区：
文献类型：
--
作者：
Ludtke, S;He, K;Huang, H
Mainin 2是在非洲爪蛙(Xeonpus Laevis)皮肤中发现的一种23个残基的抗菌肽。它属于一大类直接与脂质双层相互作用的α-螺旋多肽。目前，在分子水平上对这种肽/脂相互作用的性质知之甚少。我们已经进行了一系列片层X射线衍射实验，以提供对这种相互作用的本质的一些洞察。我们发现，当浓度低于裂解的临界浓度时，多肽导致膜厚度与多肽浓度大致成比例地减小。我们进一步证明，这种变薄与多肽在这些浓度下吸附在脂质双层的头基区的模型是一致的。这种稀释的能量成本也可以解释为什么这种肽在高浓度下插入。我们已经证明，丙氨西林与二植酰磷脂酰胆碱的相互作用存在类似的相互作用，它应该适用于各种多肽/脂类体系。
Magainin 2 is a 23-residue antibiotic peptide found in the skin of Xeonpus laevis (African clawed frog). It belongs to a broad class of alpha-helical peptides which interact directly with the lipid bilayer. Very little is presently known about the nature of this peptide/lipid interaction on the molecular level. We have performed a sequence of lamellar X-ray diffraction experiments to provide some insight into the nature of this interaction. We have found that, at concentrations below the critical concentration for lysis, the peptide causes the membrane thickness to decrease roughly in proportion to the peptide concentration. We further show that this thinning is consistent with a model where the peptide adsorbs within the headgroup region of the lipid bilayer at these concentrations. The energy cost of this thinning may also explain why the peptide inserts at high concentrations. We have already shown that a similar interaction exists for alamethicin interacting with diphytanoylphosphatidylcholine, and it should hold for a wide variety of peptide/lipid systems.