Collaborative Research: Intrinsic Gas-phase Properties of Amino Acids and Peptides: Thermochemistry, Fragmentation Mechanisms, H/D exchange and IRMPD Spectroscopy

有了这个奖项，化学结构、动力学和机制项目将支持威廉玛丽学院的约翰·c·普茨玛教授和老道明大学的詹妮弗·普茨玛教授的合作研究。John Poutsma教授采用基于质谱的实验来研究氨基酸结构与其气相能量特性之间的微妙相互作用。他正在研究一类被称为非蛋白氨基酸（NPAA）的化合物，这种化合物天然存在于植物和真菌中，但不用于蛋白质合成。许多NPAAs对人类和其他动物有毒，部分原因是它们与20种常见的蛋白质氨基酸（PAA）中的一种或多种结构相似。NPAAs可以在多种生物途径中与PAAs竞争，包括错误地结合到蛋白质和肽中。这些实验将进一步了解NPAAs作为分离实体和纳入小肽时的内在化学性质。Jennifer Poutsma教授正在进行密度泛函理论计算，以支持和指导实验研究。这两个研究项目通过培养本科生研究人员，将研究和教育结合起来。本提案中列出的绝大多数研究项目都是由威廉玛丽大学和老道明大学的本科生进行的。进行独立研究不仅可以教会这些学生发现的乐趣，还可以教会他们如何处理和处理伴随现实世界科学而来的不可避免的失败。在本研究中，采用扩展动力学方法在三重四极杆仪器上测定了二肽的固有气相热化学性质。具体来说，pi正在研究含有脯氨酸或其非蛋白质氨基酸类似物之一的氮杂丁-2-羧酸或管果酸的二肽的气相酸碱化学。他们正在努力确定环大小和构象柔韧性对这些物种酸碱性质的影响，目的是将这些知识应用于更好地理解在含脯氨酸肽的低能串联质谱实验中选择性片段的机制。

With this award, the Chemical Structure, Dynamics and Mechanisms program is supporting the Collaborative research of Professor John C. Poutsma at the College of William and Mary and Professor Jennifer Poutsma at Old Dominion University. Professor John Poutsma employs mass spectrometry-based experiments to study the subtle interplay between the structure of amino acids and their gas-phase energetic properties. He is studying a class of compounds known as non-protein amino acids (NPAA), which are found naturally in plants and fungi, but are not used in protein synthesis. Many NPAAs are toxic to humans and other animals in part due to structural similarity to one or more of the twenty common protein amino acids (PAA). NPAAs can compete with PAAs in a variety of biological pathways including being mis-incorporated into proteins and peptides. These experiments will further understanding of the intrinsic chemistry of NPAAs as isolated entities and when incorporated into small peptides. Professor Jennifer Poutsma is performing density functional theory calculations that support and guide the experimental studies. Both research programs integrate research and educational components through the training of undergraduate researchers. The vast majority of the research projects outlined in this proposal are being performed by undergraduates at William and Mary and Old Dominion University. Performing independent research helps to teach these students not only the joy of discovery but also how to handle and work though the inevitable failures that accompany real-world science. In this research, the intrinsic gas-phase thermochemical properties of di-peptides are being determined using the extended kinetic method in a triple quadrupole instrument. Specifically, the PIs are studying the gas-phase acid-base chemistry of dipeptides that contain proline or one of its non-protein amino acid analogs azetidine-2-carboxylic acid or pipecolic acid. Thar are working to determine the effects of ring-size and conformational flexibility on the acid-base properties of these species with the goal of applying this knowledge towards a better understanding the mechanisms for selective fragmentations in low-energy tandem mass spectrometry experiments of proline-containing peptides.