Nakamura Takefumi, Takahashi Hideo, Takeuchi Koh, Kohno Toshiyuki, Wakamatsu Kaori, Shimada Ichio
Japan Biological Information Research Center, Japan Biological Informatics Consortium, Tokyo 135-0064, Japan.
Biophys J. 2005 Dec;89(6):4051-5. doi: 10.1529/biophysj.105.066910. Epub 2005 Sep 16.
Membrane-peptide interactions are involved in many crucial biological and pharmacological activities. To clarify the interaction mode of membrane-peptide complexes, it is important to analyze both the dynamic properties and the contact residues of the membrane-bound peptide. In this study, we investigated the dynamic properties of a peptide bound to a lipid bilayer, using relaxation and amide-water exchange analyses, and directly determined the membrane-peptide interface, using the cross-saturation method. For the models of a lipid bilayer and a peptide, isotropic bicelles and mastoparan were used, respectively. The results indicate that mastoparan had a heterogeneous distribution of motion over various timescales and interacted with the lipid bilayer by using its hydrophobic side; the molecule was located within the lipid bilayer rather than on the surface, as thought previously. This study shows that the cross-saturation method is useful for determining the interface of not only protein-protein but also membrane-peptide complexes.
膜 - 肽相互作用涉及许多关键的生物学和药理学活性。为了阐明膜 - 肽复合物的相互作用模式，分析膜结合肽的动态特性和接触残基非常重要。在本研究中，我们使用弛豫和酰胺 - 水交换分析研究了与脂质双层结合的肽的动态特性，并使用交叉饱和方法直接确定了膜 - 肽界面。对于脂质双层和肽的模型，分别使用了各向同性双分子层和马蜂毒素。结果表明，马蜂毒素在不同时间尺度上具有不均匀的运动分布，并通过其疏水侧与脂质双层相互作用；该分子位于脂质双层内而非如先前所想位于表面。这项研究表明，交叉饱和方法不仅对于确定蛋白质 - 蛋白质复合物的界面，而且对于确定膜 - 肽复合物的界面都很有用。
