STUDYING THE ENERGY LANDSCAPE OF AN ALPHA HELIX USING 2D IR SPECTROSCOPY

本子项目是利用由NIH/NCRR资助的中心赠款提供的资源的众多研究子项目之一。子项目和研究者（PI）可能已经从另一个NIH来源获得了主要资金，因此可以在其他CRISP条目中表示。列出的机构是中心的，不一定是研究者的机构。二维红外光谱（2D IR）能够测量酰胺基团之间的振动耦合，类似于二维核磁共振测量核自旋耦合。由于偶联对肽的三维结构很敏感，因此在二维IR中观察到的交叉峰应该告诉我们肽的二级和三级结构。通过这种方式，我们应该能够监测α -螺旋的局部运动，并将这些运动与结构变化联系起来。结合模拟，该技术将揭示更详细的洞察肽内振动耦合及其结构意义。我们建议在α -螺旋模型肽中插入同位素标记（13C=16O和13C=18O），通过实验（使用2D-IR技术）研究结构动机对振动耦合的影响。

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. Two-dimensional infrared spectroscopy (2D IR) is capable of measuring the vibrational coupling between amide groups, analogous to 2D NMR measuring nuclear spin coupling. Because the coupling is sensitive to the peptide's 3D structure, the cross peaks observed in 2D IR should tell us about the peptide's secondary and tertiary structure. In this way, we should be able to monitor the motions of localized pieces of the alpha-helix, and relate these motions to changes in structure. In conjunction with simulations, this technique will reveal a much more detailed insight into the intra-peptide vibrational coupling and its structural significance. We propose to insert isotopically labels (13C=16O and 13C=18O) into alpha-helix model peptides to study experimentally (using 2D-IR techniques) the impact of structural motives on vibrational coupling.