Dynamics of Electronically Excited States - Biomolecules in the Gas Phase

在这个由化学系实验物理化学项目资助的奖项中，匹兹堡大学的David W.Pratt教授和他的本科生、研究生和博士后将在分子束和超音速喷射的无碰撞环境中对气相生物分子进行高分辨率的电子、振动和旋转光谱测量。工作在紫外光和啁啾脉冲傅立叶变换微波(CP-FTMW)技术下的单频连续环形染料激光器将被用来表征氨基酸、小肽和核酸碱基对，作为孤立物种并与弱结合溶剂分子相结合。普拉特研究小组将确定所有物种在气相中沿着热可访问的振动坐标的结构、电偶极矩和动力学性质，包括化学反应物种。这些物种包括“Foldons”，即启动大蛋白质折叠的短氨基酸序列；绿色荧光蛋白的发色团；活跃于味觉和嗅觉的手性分子；以及包含不同生物分子的水团。他们将专注于这类物种的内在二级结构及其在电子基态和激发态中的电荷分布，从而建立与光生物学和光诱导的电荷重新分配的联系，这是生物功能所必需的。除了被支持的研究的更广泛的科学影响外，普拉特教授继续为他的研究学生提供出色的科学培训。他积极参与为非理科专业本科生编写教材。此外，普拉特教授目前正与匹兹堡大学学习与研究发展中心、教育学院和匹兹堡公共教育委员会合作，为宾夕法尼亚州联邦的中学科学教师提供专业发展机会。

In this award, funded by the Experimental Physical Chemistry Program of the Chemistry Division, Prof. David W. Pratt of the University of Pittsburgh and his undergraduate, graduate, and postdoctoral research students will conduct high resolution electronic, vibrational, and rotational spectroscopic measurements of gas phase biomolecules in the collision-free environment of molecular beams and supersonic jets. Single frequency, CW ring dye lasers operating in the UV and chirped-pulse Fourier transform microwave (CP-FTMW) techniques will be employed to characterize amino acids, small peptides, and nucleic acid base pairs, both as isolated species and in combination with weakly bound solvent molecules The Pratt research group will determine the structures, electric dipole moments and dynamical properties of all species along thermally accessible vibrational coordinates, including chemically reactive ones, in the gas phase. These species include "foldons", short sequences of amino acids that initiate the folding of large proteins; the chromophore of green fluorescent protein; chiral molecules active in tasting and smelling; and water clusters containing different biomolecules. They will focus on the intrinsic secondary structures of such species and their charge distributions in both electronic ground states and excited states, thereby establishing a link to photobiology and the light-induced redistributions of charge that are essential to biological function. Besides the broader scientific impacts of the research being supported, Prof. Pratt continues to provide excellent scientific training to his research students. He is actively involved in developing curricular materials for undergraduates not majoring in the sciences. Additionally, Prof. Pratt is currently working with the University of Pittsburgh's Learning & Research Development Center, the School of Education and the Pittsburgh Board of Public Education to provide professional development opportunities for middle school science teachers in the Commonwealth of Pennsylvania.