NEAR-ULTRAVIOLET RAMAN STUDIES OF CYTOCHROME P450

我们已经观察到详细的和信息丰富的共振拉曼光谱 血红素蛋白，如细胞色素P450、细胞色素c、肌红蛋白和 血红蛋白。深蓝和近紫外光的激光激发 共振吸收带导致信号强度大大增强 与血红素假体组相关。我们的目标是扩大我们的 对细胞色素P450等结构和功能的理解 利用拉曼光谱等快速发展的血红素蛋白体系 基于激光的分光镜。这一整体项目有广泛的 尤其是涉及细胞色素P450的健康相关影响 一般的血红素蛋白。许多化疗药物以及 多环致癌物由P450系统代谢。而且，所有的 涉及P450蛋白的代谢紊乱一定与此有关 研究。对活性部位结构和结构的基本了解 P450在分子水平上的功能将导致更好的洞察力 对于那些关心这些疾病的治疗的人来说，无论是哪一级。 这些研究将使用拉曼激发剖面测量， 允许将关键的电子-核耦合参数从 结合吸收和拉曼数据。对吸收的仔细研究 拉曼线形也将作为以下函数来执行 超快激光之后的温度和作为时间的函数 激动人心。瞬时二向色性、双折射和超拉曼光谱 光谱学将被开发为生物材料的新探针。 涉及定点突变、pH、温度的样品扰动 和光泵浦也在计划中。时间分辨蛋白质动力学 从飞秒到千秒的时间尺度。 配基的光解和电子输运现象与热 松弛和非辐射衰变过程将被研究。 肌红蛋白和细胞色素P450 cam的单晶样品将 研究了它作为取向和激发波长的函数。 关于配基与血红素蛋白结合的理论工作，电子 还将研究转移和共振的光-物质相互作用。

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. 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. 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. 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 and as a function of time, subsequent to ultrafast laser excitation. Transient dichroism and birefringence as well as hyper-Raman spectroscopy will be developed as new probes of biological materials. Sample perturbations involving site directed mutagenesis, pH, temperature and optical pumping are also scheduled. Time resolved protein dynamics will be followed from the femtosecond to the kilosecond timescale. 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 be studied as a function of orientation and excitation wavelength. Theoretical work involving ligand binding to heme proteins, electron transfer and resonant light-matter interactions will also be pursued.