Resonance Raman Studies of Mammalian Heme Proteins

该计划的长期研究目标是实现血红素蛋白质的显着功能多样性的分子水平的理解，这些物质在生物系统中至关重要，一般来说，特别是在人类生理学中。在参与和促进许多关键的生物化学过程中，包括氧和电子传递，以及消除内部产生和环境积累的毒素，血红素位点的固有反应性通过与相关多肽的分子间相互作用有效地调节，并通过与其他蛋白质和小调节分子的分子间相互作用进一步控制。除了更稳定的初态和终态外，人们对短暂但功能重要的瞬态或中间态也很感兴趣。本研究计划的基本策略是应用强大的光谱探针，特别是共振拉曼和时间分辨共振拉曼技术，与天然的和策略性操纵的蛋白质相结合，以揭示这种血红素基团反应性调节的分子基础。事实上，通常情况下，这些特定的方法是这些位点的唯一有效的探针。在本提议中要解决的具体系统是涉及哺乳动物生理学的三种重要类别的血红素蛋白;细胞色素P450，其催化外源性物质的转化，使它们为消除做好准备;鸟苷酸环化酶，神经递质NO的最重要的受体分子，其在人类生理学中起关键的调节功能;以及最后，一组血红素蛋白。 过氧化物酶在人类抵御入侵微生物的过程中起着关键作用。

The long term research goals of this program are to attain a molecular level understanding of the remarkable functional diversity of heme proteins, substances that are of critical importance in biological systems, in general, and in human physiology in particular. In participating in and facilitating many critical biochemical processes, including oxygen and electron transport, as well as the elimination of internally generated and environmentally accumulated toxins, the inherent reactivity of the heme sites are effectively regulated by intermolecular interactions with the associated polypeptides and further controlled by intermolecular interactions with other proteins and small regulatory molecules. In addition to the more stable initial and final states, a great deal of interest is attached to the fleeting, but functionally important, transient or intermediate states.The essential strategy of this research program is to apply powerful spectroscopic probes, especially resonance Raman and time-resolved resonance Raman techniques, to the native and strategically manipulated proteins in order to reveal the molecular basis for this modulation of heme group reactivity. In fact, it is often the case that these particular methods are uniquely effective probes of these sites. The specific systems to be addressed in the present proposal are three important classes of heme proteins involved in mammalian physiology; cytochromes P450, which catalayze the conversion of xenobiotics, preparing them for elimination; guanylate cyclase, the most important receptor molecule for the neurotransmitter, NO, which serves a crucial regulatory function in human physiology; and, finally, a group of enzymes known as peroxidases that play a critical role in human defence against invading microorganisms.