Exploring peptide membrane interaction using surface plasmon resonance: Differentiation between pore formation versus membrane disruption by lytic peptides
Exploring peptide membrane interaction using surface plasmon resonance: Differentiation between pore formation versus membrane disruption by lytic peptides
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DOI：
10.1021/bi0267846
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发表时间：
2003-01-21
期刊：
影响因子：
2.9
通讯作者：
Shai, Y
中科院分区：
文献类型：
--
作者：
Papo, N;Shai, Y
裂解肽由一大类膜活性肽组成，用于所有生物体的防御和进攻系统。区分它们与膜的相互作用模式对于理解这些肽如何选择它们的靶细胞至关重要。在这里，我们利用 SPR 研究裂解肽和脂质双层（L1 传感器芯片）之间的相互作用。对混合单层（HPA 传感器芯片）的研究表明，SPR 是一种强大的工具，可用于实时监测膜活性肽的作用模式所涉及的步骤，其中一些以前无法通过其他技术直接检测到，本文首次报道。我们研究了代表两个主要家族的肽的作用模式：（i）蜂毒，蜂毒肽，作为形成跨膜孔的非细胞选择性肽的模型；（ii）magainin和蜂毒肽的非对映异构体（四个氨基酸被它们的D对映体取代），作为细菌选择性非孔形成肽的模型。将 SPR 数据拟合到不同的相互作用模型可以区分两个主要步骤：膜结合和膜插入。蜂毒肽与 PC/胆固醇的结合比其非对映异构体和 magainin 强 450 倍，主要是因为它插入到内部小叶中（结合能的 2/3），而其他两种则不然。相比之下，所有肽与带负电的 PE/PG 单层膜和双层膜的结合（在第一步和第二步中）仅存在轻微差异，表明内部小叶对其与 PE/PG 双层膜的结合仅略有贡献。此外，与 PC/胆固醇相比，细胞选择性肽与 PE/PG 的结合强 100 倍，这仅是由于对外层带负电的头部基团的静电吸引所致。这些结果清楚地区分了两种一般机制：蜂毒肽仅在两性离子膜中形成孔，以及对带负电的膜中的所有肽产生类似去垢剂的作用（地毯机制），这与它们的生物学功能一致。
Lytic peptides comprise a large group of membrane-active peptides used in the defensive and offensive systems of all organisms. Differentiating between their modes of interaction with membranes is crucial for understanding how these peptides select their target cells. Here we utilized SPR to study the interaction between lytic peptides and lipid bilayers (L1 sensor chip). Using studies also on hybrid monolayers (HPA sensor chip) revealed that SPR is a powerful tool for obtaining a real-time monitoring of the steps involved in the mode of action of membrane-active peptides, some of which previously could not be detected directly by other techniques and reported here for the first time. We investigated the mode of action of peptides that represent two major families: (i) the bee venom, melittin, as a model of a non-cell-selective peptide that forms transmembrane pores and (ii) magainin and a diastereomer of melittin (four amino acids were replaced by their D enantiomers), as models of bacteria-selective non-pore-forming peptides. Fitting the SPR data to different interaction models allows differentiating between two major steps: membrane binding and membrane insertion. Melittin binds to PC/cholesterol similar to450-fold better than its diastereomer and magainin, mainly because it is inserted into the inner leaflet (2/3 of the binding energy), whereas the other two are not. In contrast, there is only a slight difference in the binding of all the peptides to negatively charged PE/PG mono- and bilayer membranes (in the first and second steps), indicating that the inner leaflet contributes only slightly to their binding to PE/PG bilayers. Furthermore, the 100-fold stronger binding of the cell-selective peptides to PE/PG as compared with PC/cholesterol resulted only from electrostatic attraction to the negatively charged headgroups of the outer leaflet. These results clearly differentiate between the two general mechanisms: pore formation by melittin only in zwitterionic membranes and a detergent-like effect (carpet mechanism) for all the peptides in negatively charged membranes, in agreement with their biological function.