Infrared spectroscopic studies of ionic and neutral biomolecules and their solvated complexes

建议的研究集中在中性和离子分子和配合物的结构解析，特别是那些可以参与弱分子内键合。 在自然状态下，蛋白质和其他生物分子被多次质子化。它们也可以与金属阳离子结合，这通常是生物活性所需的。 拟议的研究将提供洞察到显着的弱分子内相互作用，这是存在于生物相关的分子，通过研究这些物种的红外光谱分离在稀有气体矩阵在低温下，他们可以存储和研究不确定。 与分子另一部分的相互作用程度（分子内键合）可以通过红外吸收位置的位移来研究。 例如，当甘氨酸与钠阳离子结合时，预期异构体之一在羰基氧和氨基氢之间表现出强的分子内氢键。 N-H伸缩被认为从正常的N-H伸缩红移了大约800个波数。 将研究顺序溶剂化（用1、2或更多溶剂分子，如水）生物学上感兴趣的离子和中性物的效果，以弥合气相分子的固有性质与分子在其自然溶剂化状态下的固有性质之间的差距。 与拟议的实验，我们将能够评估的结构变化发生在每个阶段的溶剂化。这项研究有望在确定生命组成部分的结构以及溶剂对结构的影响方面发挥重要作用。 这将导致对生物分子的作用和溶剂在生物活性中的作用的更详细，更基本的理解。 此外，这项研究将提供生物离子和中性粒子的光谱特征，最终有助于将红外光谱用于诊断目的。

The proposed research is focused on the structure elucidation of both neutral and ionic molecules and complexes, especially those which can participate in weak intramolecular bonding.  In their natural state, proteins and other biological molecules are multiply protonated. They can also be bound to metal cations and this is often required for biological activity.  The proposed research will provide insight into the salient weak intramolecular interactions which are present in biologically relevant molecules by studying the infrared spectra of these species isolated in rare-gas matrices at cryogenic temperatures where they can be stored and studied indefinately.  The degree of interaction with another portion of the molecule (intramolecular bonding) can be studied by the shifts in  position of the infrared absorption.  For example, when glycine is bound to a sodium cation, one of the isomers is expected to exhibit strong intramolecular hydrogen bonding between a carbonyl oxygen and an amino hydrogen.  The N-H stretch is seen to red-shift by some 800 wavenumbers from that of a normal N-H stretch.   The effect of sequentially solvating (with 1, 2 or more solvent molecules such as water) biologically interesting ions and neutrals will be studied in order to bridge the gap between the intrinsic properties of the gas-phase molecule and those of the molecule in its natural, solvated state.  With the proposed experiments we will be able to assess the structural changes which occur at each stage solvation. This research is expected to play an important role in determining the structure, and the effect of solvent on the structure, of life's building blocks.  This will lead to a more detailed, fundamental understanding of the role of the biomolecule and the role of solvent in biological activity.  Furthermore, this research will provide spectral signatures for biological ions and neutrals which can eventually aid in the use of infrared spectroscopy for diagnostic purposes.