Proton Transfer in Biomolecules

有机动力学计划正在支持雅各布·W。Petrich，Mark S. Gordon和乔治A.爱荷华州化学系的克劳斯说， 大学在他们的合作研究激发态质子 在生物分子中转移。 通过结合超快 光谱学、从头算量子化学计算和合成 有机化学，他们将发展对激发态的理解 质子转移反应 两个模型系统，7-氮杂吲哚和金丝桃素， 这是这些研究的重点。 虽然激发态质子转移 在这些系统中起着关键作用，它们代表了两个非常重要的 不同的情况下，质子转移是强烈介导的 7-氮杂吲哚中的溶剂，但仅受溶剂的影响可忽略不计。 金丝桃素 理论和超快光谱学之间的相互作用将 揭示了内部和外部的相对贡献 这些质子转移反应中的分子间相互作用。 带正电荷的氢离子（质子）从一个原子移动到另一个原子。 另一个代表最简单的化学反应之一，然而， 化学反应是各种化学反应的核心， 生物过程。 在某些情况下，质子转移可能会引发 通过光的作用，它增加了能量（“激发”） 分子释放质子。 尽管概念简单， 质子转移反应实际上可以通过相当复杂的 分子水平的过程。 这些合作者将检查两个类 不同类型的激发态质子 转移反应 一组化合物，经常用作 酶的结构和反应化学，强烈地受到 分子溶解于其中的溶剂的性质，而 另一种，以金丝桃素为代表，一种有趣的化合物， 当被光激活时，抗病毒作用几乎不受 溶剂后 这些研究将有助于开发分子水平的 了解这些关键的质子转移过程。

The Organic Dynamics Program is supporting Jacob W. Petrich, Mark S. Gordon, and George A. Kraus of the Department of Chemistry of Iowa State University in their collaborative studies of excited-state proton transfer in biomolecules. Through a combination of ultrafast spectroscopy, ab initio quantum chemical calculations, and synthetic organic chemistry, they will develop an understanding of excited-state proton transfer reactions. Two model systems, 7-azaindole and hypericin, form the focus of these studies. Although excited-state proton transfer plays a key role in each of these systems, they represent two very different cases, in that the proton transfer is strongly mediated by solvent in 7-azaindole, but only negligibly influenced by solvent in hypericin. The interplay between theory and ultrafast spectroscopy will lead to revelation of the relative contributions of intra- and intermolecular interactions in these proton transfer reactions. Movement of positively-charged hydrogen ions (protons) from one atom to another represents one of the simplest chemical reactions, yet such reactions lie at the heart of an astounding variety of chemical and biological processes. In some cases, proton transfer may be initiated through the action of light, which adds energy to (`excites`) the molecule giving up the proton. Despite their conceptual simplicity, proton transfer reactions may in fact occur through rather complex molecular-level processes. These collaborators will examine two classes of compounds displaying very different types of excited-state proton transfer reactions. One group of compounds, frequently used as probes of enzyme structure and reaction chemistry, is influenced strongly by the nature of the solvent in which the molecule is dissolved, while the other, typified by hypericin, an intriguing compound which displays anti-viral action when activated by light, is barely affected by the solvent. These studies will help to develop a molecular-level understanding of these critical proton transfer processes.