The effects of hydrophobic mismatch between phosphatidylcholine bilayers and transmembrane α-helical peptides depend on the nature of interfacially exposed aromatic and charged residues
The effects of hydrophobic mismatch between phosphatidylcholine bilayers and transmembrane α-helical peptides depend on the nature of interfacially exposed aromatic and charged residues
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DOI：
10.1021/bi0257686
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发表时间：
2002-07-02
期刊：
影响因子：
2.9
通讯作者：
Killian, JA
中科院分区：
文献类型：
--
作者：
de Planque, MRR;Boots, JWP;Killian, JA
在这项研究中，我们研究了不同的芳香侧链和带正电荷的侧链（通常位于蛋白质跨膜片段的侧翼）可以在多大程度上影响脂质-肽相互作用。研究了由磷脂酰胆碱和具有不同侧翼残基的疏水性α-螺旋肽组成的模型系统。将肽掺入相对较厚和相对较薄的脂质双层中，以产生肽双层疏水错配，并分析对脂质结构的补偿作用。当双层厚度相对较长时，侧翼为芳香族侧链、Trp、Tyr 和 Phe 的肽都会诱导脂酰基链的显着排序，而侧翼为带电残基 Lys、Arg 和 His 的肽则不会。然而，当肽相对于双层的厚度相对较短时，它们对脂质组织的影响并不主要取决于它们的芳香或带电特性。侧翼为 Trp、Tyr、Lys 或（在低 pH 下）His 残基的肽可有效诱导错配消除立方相和倒六方相，而侧翼为 Phe、Arg 或（在中性 pH 下）His 残基的类似物不能诱导倒六方相。对错配的不同反应可能反映了所研究的残基的不同界面亲和力。
this study, we investigated the extent to which different aromatic and positively charged side chains, which often flank transmembrane segments of proteins, can influence lipid-peptide interactions. Model systems consisting of phosphatidylcholine and hydrophobic a-helical peptides with different flanking residues were investigated. The peptides were incorporated in relatively thick and in relatively thin lipid bilayers to create a peptide-bilayer hydrophobic mismatch, and the compensating effects on lipid structure were analyzed. When relatively long with respect to the thickness of the bilayer, the peptides that are flanked by the aromatic side chains, Trp, Tyr, and Phe, all induce a significant ordering of the lipid acyl chains, while the peptides flanked by the charged residues Lys, Arg, and His do not. However, when the peptides are relatively short with respect to the thickness of the bilayer, their effect on lipid organization does not depend primarily on their aromatic or charged character. Peptides flanked by Trp, Tyr, Lys, or (at low pH) His residues are effective in inducing mismatch-relieving cubic and inverted hexagonal phases, while analogues flanked by Phe, Arg, or (at neutral pH) His residues cannot induce an inverted hexagonal phase. The different responses to mismatch might reflect the different interfacial affinities of the residues that were investigated.