PROBING THE PROTON GATING DYNAMICS OF THE INFLUENZA VIRUS M2 CHANNEL USING FCS

这个子项目是许多研究子项目中的一个 由NIH/NCRR资助的中心赠款提供的资源。子项目和 研究者（PI）可能从另一个NIH来源获得了主要资金， 因此可以在其他CRISP条目中表示。所列机构为 研究中心，而研究中心不一定是研究者所在的机构。 M2是具有单跨膜（TM）α螺旋伸展的97个残基的蛋白质。M2在膜环境中同源四聚化形成质子选择性通道。跨膜部分（M2 tm）是序列SSDPLVVAASIIGILHLLILWILDRL的25个氨基酸的肽。流感病毒M2整合膜蛋白的离子通道活性在病毒的生命周期中起着重要作用。有人提出，四个跨膜螺旋中的每一个中的Trp 41对于M2的pH门控质子通道至关重要。发现跨膜序列中His（H）的突变导致质子选择性的丧失，并且Trp（W）氨基酸的突变允许质子流出。因此，本项目的目标是使用荧光相关光谱结合激发态电子转移（色氨酸和标记的染料探针之间）探测吲哚环的构象动力学作为pH值的函数。由此获得的信息应该使我们能够更好地了解M2通道的质子门控机制。我们还想研究小分子金刚烷胺和金刚乙胺的作用，它们被发现可以阻断离子通道。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. M2 is a 97 residue protein with a single transmembrane (TM) alpha helical stretch. M2 homotetramerizes to form a proton selective channel in a membrane environment. The transmembrane section (M2tm) is a 25 amino acid peptide of the sequence SSDPLVVAASIIGILHLILWILDRL. The ion channel activity of the influenza virus M2 integral membrane protein plays an important role in the life cycle of the virus. It has been proposed that Trp 41 in each one of the four transmembrane helices is crucial for the pH-gated proton channel of M2. It was found that mutation of teh His (H) in the transmembrane sequence leads to a loss of the proton selectivity and mutation of the Trp (W) amino acid allows for the outflow of protons. Thus, the goal of this project is to use fluorescence correlation spectroscopy in conjunction with excited state electron transfer (between Trp and a labeled dye probe) to probe the conformational dynamics of the indole rings as a function of pH. The information thus obtained should allow us to gain a better understanding of the proton gating mechanism of the M2 channel. We also would like to investigate the action of the small molecules Amantadine and Rimantadine which were found to block the ion channel.