RESONANCE RAMAN STUDIES OF HEME PROTEINS

我们已经观察到详细和翔实的共振拉曼光谱从 血红素蛋白质细胞色素P450和引起近紫外激光的细胞色素 激发 我们建议将我们的测量扩展到可见光， 我们的可调谐染料激光器，并进一步进入紫外线使用谐波 产生和光学多通道分析仪（OMA）检测。 我们计划 特别关注重要催化剂的拉曼光谱研究 中间状态，如还原和氧化的P450复合物， 为了帮助推断参与氧结合和切割的机制， 这类重要的代谢酶。 长期目标是 使用共振拉曼散射来获得关于活性的新信息 细胞色素P450和其他血红素蛋白的位点结构和功能， 为了更好地理解金属卟啉的光吸收， 谱 光敏中间态将使用OMA进行研究 检测和我们的双臂拉曼差分光谱仪将被利用 在各种涉及低温的实验中， 标签，pH和压力扰动等理论含义 三体简正模振荡器模型的研究将进一步进行， 基于“变换”的吸收和拉曼激发理论 轮廓测量将应用于血红素蛋白系统， 细胞色素c、血红蛋白和细胞色素P450。 荧光激发 血红素系统的轮廓测量将使用我们新开发的 绝对量子产率测定技术。 光声 光谱学将被用来帮助我们理解这些荧光 实验和伴随的快速非辐射弛豫通道 存在于血红素蛋白系统中。

We have observed detailed and informative resonance Raman spectra from the heme proteins cytochrome P450 and cytochrome causing near ultraviolet laser excitation. We propose to extend our measurements into the visible using our tunable dye laser and further into the ultraviolet using harmonic generation and optical multichannel analyzer (OMA) detection. We plan to specifically focus on Raman spectral studies of important catalytic intermediate states such as the reduced and oxygenated P450 complexes in order to help deduce mechanisms involved in oxygen binding and cleavage in this important class of metabolic enzymes. The long term objective is to use resonance Raman scattering to gain new information about the active site structure and function of cytochrome P450 and other heme proteins and to achieve a better understanding of metalloporphyrin optical absorption spectra. Photosensitive intermediate states will be studied using OMA detection and our dual arm Raman difference spectrometer will be utilized in a variety of experiments involving cryogenic temperatures, isotopic labels, pH and pressure perturbations, etc. The theoretical implications of 3-body normal mode oscillator models will be further pursued and the "transform" based theories relating absorption and Raman excitation profiled measurements will be applied to heme protein systems such as cytochrome c, hemoglobin and cytochrome P450. Fluorescence excitation profile measurements of heme systems will be made using our newly developed technique for absolute quantum yield determination. Photoacoustic spectroscopy will be used to aid in our understanding of these fluorescence experiments and the accompanying rapid nonradiative relaxation channels present in heme protein systems.