Dynamic control of protein structure by cation-π interaction

通过阳离子-π相互作用动态控制蛋白质结构

• 批准号: 16350003
• 负责人: TAKEUCHI Hideo
• 金额: $ 10.18万
• 依托单位: Tohoku University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 2004
• 资助国家: 日本
• 起止时间: 2004 至 2006
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-16350003/
• 关键词: Protein; Cation-π interaction; Neuromedin; Fluorescence Spectra; UV Resonance Raman Spectra; Influenza; Virus; Ion Channel; 構造; 円偏光二色性; 紫外共鳴ラマン分光法

We have studied the effects of interaction between a positive charge and π electrons, i.e. cation-π interaction, on the structural formation and dynamics of proteins by circular dichroism (CD), fluorescence, and UV resonance Raman spectroscopy. The peptides and proteins studied are neuromedin B, neuromedin C, and the transmembrane region of influenza B virus BM2 protein (BM2-TMP). The cation-π interaction between His^+ and Trp was found to be unable to control the secondary structures of neuromedin B and C, suggesting that such cation-π interactions do not so much contribute to protein structural stability. However, analogous cation-π interactions play an important role in gating a proton channel formed by BM2-TMP in lipid bilayers, demonstrating that cation-π interactions can control the functioning of a protein by modifying its local structure near functionally important regions. In addition, cation-π interaction between Cu^<2+> and Trp was found to cause not only a shift and intensity change of UV absorption of the Trp indole ring but also to generate a negative signal in CD spectra. The negative CD signal is expected to serve as a new marker of cation-π interaction between Cu^<2+> and Trp in proteins. As shown in the case of the proton channel formed by BM2-TMP, cation-π interactions could play important roles in structural dynamics of proteins associated with their functioning. Although the present proposal about the role of cation-a interaction in protein functioning need to be further tested in many other proteins, the present study has provided the basis of such future studies.

我们通过圆二色性 (CD)、荧光和紫外共振拉曼光谱研究了正电荷和 π 电子之间的相互作用（即阳离子-π 相互作用）对蛋白质结构形成和动力学的影响。神经调节素 B、神经调节素 C 和乙型流感病毒 BM2 蛋白的跨膜区 (BM2-TMP) 被发现无法控制 His^+ 和 Trp 之间的阳离子-π 相互作用。神经调节肽 B 和 C 的二级结构，表明这种阳离子 - π 相互作用对蛋白质结构稳定性的贡献不大，然而，类似的阳离子 - π 相互作用在门控脂质双层中 BM2-TMP 形成的质子通道中发挥着重要作用。 ，证明阳离子-π 相互作用可以通过改变功能重要区域附近的局部结构来控制蛋白质的功能。此外，发现 Cu^<2+> 和 Trp 之间的阳离子-π 相互作用不仅会引起变化和强度。改变色氨酸吲哚环的紫外吸收，而且还在CD光谱中产生负信号，预期负CD信号可作为蛋白质中Cu ^ 2+ 和色氨酸之间的阳离子-π相互作用的新标记。就 BM2-TMP 形成的质子通道而言，阳离子-π 相互作用可能在相关蛋白质的结构动力学及其功能中发挥重要作用，尽管目前关于阳离子-α 相互作用在蛋白质功能中的作用的建议需要进一步研究。在许多其他蛋白质中进行了测试，本研究为今后的此类研究奠定了基础。