NEAR ULTRAVIOLET RAMAN STUDIES OF CYTOCHROME P450

我们观察到了血红素的详细的共振拉曼光谱 蛋白质如细胞色素P450、细胞色素c、肌红蛋白和血红蛋白。 深蓝激光激发和近紫外共振吸收 条带导致与血红素相关的信号强度大大增强 辅基 我们的目标是扩展我们对结构的理解， 细胞色素P450和其他血红素蛋白系统的功能， 拉曼和其他快速发展的激光光谱学。 这些 研究将采用拉曼激发轮廓测量， 电子-核耦合参数，以提取从组合 吸收和拉曼数据。 仔细研究吸收和拉曼 线形也将作为温度的函数进行。 样品 涉及定点诱变、pH和光泵浦的扰动 也是预定的。 时间分辨蛋白质动力学将在两个研究 纳秒和皮秒范围。 配体光解和电子 传输现象沿着热弛豫和非辐射衰变 过程将被调查。 肌红蛋白的单晶样品和 细胞色素P450 cam也将作为取向的函数进行研究， 激发波长 诱导z极化电荷的各种配体 转移激发将与晶体复合，以便检查 极化率张量的细节。 理论工作涉及 配体结合血红素蛋白，电子转移和共振光- 还将追求物质的相互作用。 合作实验 包括微波传导性，电子自旋共振和深 将引发紫外拉曼散射。 整个项目有 涉及细胞色素P450的广泛健康相关影响 特别是血红素蛋白。 许多化疗 P450系统可代谢多环致癌物。 此外，所有涉及P450蛋白的代谢紊乱都必须与 这项研究。 当然，对活性位点的基本理解 P450在分子水平上的结构和功能将导致 更好地了解那些关心治疗这些疾病在任何 水平

We have observed detailed and informative resonance Raman spectra from heme proteins such as cytochrome P450, cytochrome c, myoglobin and hemoglobin. Laser excitation in the deep blue and near ultraviolet resonant absorption bands leads to greatly enhanced signal intensities associated with the heme prosthetic group. We aim to extend our understanding of the structure and function of cytochrome P450 and other heme protein systems by the use of Raman and other rapidly developing laser based spectroscopies. These studies will employ Raman excitation profile measurements that allow key electron-nuclear coupling parameters to be extracted from the combined absorption and Raman data. Careful studies of the absorption and Raman lineshapes will also be carried out as a function of temperature. Sample perturbations involving site directed mutagenesis, pH and optical pumping are also scheduled. Time resolved protein dynamics will be studied in both the nanosecond and picosecond regimes. Ligand photolysis and electron transport phenomena along with thermal relaxation and non-radiative decay processes will be investigated. Single crystal samples of myoglobin and cytochrome P450cam will also be studied as a function of orientation and excitation wavelength. Various ligands that induce z-polarized charge transfer excitations will be complexed to the crystals in order to examine the details of the polarizability tensor. Theoretical work involving ligand binding to heme proteins, electron transfer and resonant light- matter interactions will also be pursued. Collaborative experiments involving microwave conductivity, electron spin resonance and deep ultraviolet Raman scattering will be initiated. This overall project has wide range of health related implications involving cytochrome P450 in particular and heme proteins in general. Many chemotherapeutic agents as well as polycyclic carcinogens are metabolized by P450 systems. Moreover, all metabolic disorders involving a P450 protein must relate to this research. Certainly a fundamental understanding of the active site structure and function of P450 at the molecular level will result in a better insight for those concerned with treatment of these disorders at any level.