NEAR-ULTRAVIOLET RAMAN STUDIES OF CYTOCHROME P450

我们已经观察到详细和翔实的共振拉曼光谱， 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。 深蓝和近紫外激光激发 共振吸收带导致极大增强的信号强度 与血红素辅基相关。 我们的目标是扩大我们的 了解细胞色素P450的结构和功能， 血红素蛋白质系统的利用拉曼和其他迅速发展 基于激光的光谱学 该项目具有广泛的 特别是涉及细胞色素P450的健康相关影响， 血红素蛋白 许多化学治疗剂以及 多环致癌物通过P450系统代谢。 而且所有 涉及P450蛋白的代谢紊乱一定与此有关 research. 对活性中心结构的基本理解， 在分子水平上研究P450的功能， 对于那些关心治疗这些疾病在任何水平。 这些研究将采用拉曼激发轮廓测量， 允许关键的电子-核耦合参数被提取从 结合吸收和拉曼数据。 仔细研究吸收 和拉曼线形也将作为函数进行 温度和时间的函数，随后超快激光 激发 瞬态二向色性和双折射以及超拉曼 光谱学将发展成为生物材料的新探针。 涉及定点诱变、pH值、温度的样品扰动 和光泵浦。 时间分辨蛋白质动力学 从飞秒到千秒的时间尺度。 配体光解和电子传输现象沿着热 将研究弛豫和非辐射衰变过程。 肌红蛋白和细胞色素P450 cam的单晶样品将在 作为取向和激发波长的函数进行研究。 理论工作涉及配体结合血红素蛋白，电子 还将研究光-物质的转移和共振相互作用。

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.