SPECTRAL SIGNATURES OF CHIRALITY AND CHIRALITY RECOGNITION

如果一个分子的镜像不能叠加到它自己身上，那么它就是手性的，或者说表现出“惯用手”。如果不是因为一个重要的事实，对手性和手性识别的研究将是一次纯粹的科学冒险：生物体产生的许多分子都表现出特定的惯用手。当与生物体中预期受体相匹配的一个镜像处于活动状态时，另一个镜像可能处于非活动状态或可能造成严重伤害。然而，由于镜像在许多方面都是如此相似，因此在评估和寻找这些影响的解决方案方面存在重大挑战！我的研究计划致力于通过开发1)快速可靠的手性测定方法和2)分子水平上严格的手性识别模型来为这些挑战的两个主要方面提供答案。我们在模型手性接触对和氨基酸聚集体方面的原创性工作大大推进了在分子水平上对手性识别进行严格描述的目标。这项提议包括使用最先进的激光和质谱学技术开发一种主要仪器。这一创新的新工具将能够在室温和超冷条件下测量具有特定质量/电荷比的大型生物聚集体中手性识别的红外特征，从而使人们能够前所未有地深入了解构象转换和识别事件。我们在了解手性分子如何向非手性分子传递手性信息以及在有机和无机化合物的手性测定方面做出了重要贡献。我们已经成功地展示了结合基质隔离-振动圆二色谱(VCD)技术跟踪自聚集和手性转移事件的能力，以及探测否则将极难研究的外来手性物种的能力。为了利用我们的成功，我们将探索两种尖端手性检测技术的创新应用，即VCD和拉曼光学活性光谱仪(加拿大首个此类技术)，用于糖蛋白和手性保护的金属纳米颗粒。

A molecule is chiral, or said to exhibit "handedness", if its mirror image cannot be superimposed onto itself. Research into chirality and chirality recognition would be a pure scientific adventure if not for this important fact: many of the molecules produced by organisms exhibit a specific handedness. While one mirror image that fits the intended receptor in the organism is active, the other one may be inactive or may cause severe harm. There are, however, significant challenges in evaluating and finding solutions to these implications since the mirror images are so similar in many ways! My research program is dedicated to provide answers to two main aspects of these challenges through developments of 1) fast reliable methods for chirality determination and 2) rigorous chirality recognition models at the molecular level. Our original work on model chiral contact pairs and amino acid aggregates significantly furthers the goal of a rigorous description about chirality recognition at the molecular level. This proposal includes one major instrument development using the most advanced laser and mass spectrometry technologies. The innovative new tool will enable measurements of infrared signatures of chirality recognition in large bio-aggregates with specific mass/charge ratio both at room temperature and under ultra-cold condition, allowing unprecedented insights into the conformational conversion and recognition events. We have made important contributions in understanding how chiral molecules transfer chirality information to achiral molecules and in chirality determination of organic and inorganic compounds. We have successfully demonstrated the capability of a combined matrix isolation-vibrational circular dichroism (VCD) technique for following self-aggregation and chirality transfer events and for probing exotic chiral species that would otherwise be extremely difficult to study. To capitalize on our success, we will explore innovative new applications of two cutting-edge chiral detection techniques, i.e. a VCD and a Raman optical activity spectrometer (the first of its kind in Canada) to glycoproteins and chiral protected metal nanoparticles.