PROTEIN CONTROL OF HEME REACTIVITY

血红素蛋白参与了许多重要的生理过程。 过程，包括：向组织输送氧气；衍生 营养物质氧化所储存的能量；防护性破坏 有潜在危险的过氧化氢；以及激活和消除有毒物质 污染物和致癌物。尽管有如此惊人的功能多样性， 所有这些物种都使用血红素基团作为活性成分。 确定导致这一不同功能的因素将是 对获得对正常行为的理解有明显的好处 和异常状态。这项研究计划的长期目标是 对这些不同蛋白质分子机制的阐明 与常见的血红素基团相互作用，有效调节其 反应性。基本上，我们的方法是系统地扰乱 血红素基团的结构和官能团的定量测定 使用适当的方法产生的后果。的平衡点和动力学 与氧运输蛋白结合的配体将使用 停流仪和连续氧合曲线分析仪。 将使用普遍接受的酶分析方法来表征该功能 其他血红素蛋白的修饰衍生品有待研究。为了 阐明了改变功能的分子基础，一些强有力的 光谱技术将被用来探测 以确定结构扰动的影响 关于活性中心的电子结构和反应性。 使用的光谱方法包括：共振拉曼光谱、核光谱 核磁共振、红外、圆二色谱和电子学 吸收光谱学这种多方面的方法利用了 应用于系统修饰蛋白质的各种技术 代表了阐明重要的分子控制的现实尝试 导致如此显著的功能多样性的机制。

Heme proteins are involved in a large number of physiologically important processes, including: delivery of oxygen to the tissues; derivation of stored energy from oxidation of nutrients; protective destruction of potentially dangerous peroxides; and activation and elimination of toxic pollutants and carcinogens. Despite this remarkable functional diversity, all of these species employ the heme group as the active component. Identification of the factors responsible for this varied function would be of obvious benefit for attaining an understanding of the behavior in normal and abnormal states. The long term objective of this research program is the elucidation of the molecular mechanisms by which these various proteins interact with the common heme group to effectively regulate its reactivity. Basically, our approach is to systematically perturb the structure of the heme group and quantitatively determine the functional consequences using appropriate methodology. The equilibria and kinetics of ligand binding to oxygen transport proteins will be investigated using stopped-flow instrumentation and a continuous oxygenation curve analyzer. Commonly accepted enzyme assays will be used to characterize the function of modified derivatives of other heme proteins to be studied. In order to elucidate the molecular basis of altered function, a number of powerful spectroscopic techniques will be used to probe key interactions between the heme and protein and to determine the effect of the structural perturbation on the electronic structure and reactivity of the active site. Spectroscopic methods to be used include: resonance Raman, nuclear magnetic resonance (NMR), infrared, circular dichroism (CD) and electronic absorption spectroscopy. This multifaceted approach, which utilizes a variety of techniques, applied to systematically modified proteins represents a realistic attempt to elucidate the important molecular control mechanisms responsible for such remarkable functional diversity.