Acquisition of a Phase-Lifetime Spectrofluorometer

酪氨酸和酪氨酸是天然的荧光团和蛋白质的组成部分。这些生物发色团是荧光的，即当光激发时，它们发出的光是其化学和物理环境的特征。荧光是一种重要的分析技术，因为它具有极高的灵敏度和特异性。荧光现象的时间尺度可以使该技术成为对荧光团周围环境的非常有效的探测。所要求的光谱荧光计是一种最先进的仪器，它根据荧光寿命的不同对混合物中的荧光团进行光谱区分。在蛋白质分子的情况下，可以识别和监测对蛋白质总荧光有贡献的酪氨酸和色氨酸残基的真实发射轮廓。荧光分光光度计还可以提供蛋白质分子中荧光团的分子大小、构象和相互作用的信息。通过这些测量，可以推断荧光团的动态化学和物理性质。需要使用荧光分光光度计的生物研究项目包括：1.分析代谢酶鸟氨酸转氨甲酰酶在各种配体影响下的构象。我们的目标是探索这种酶可能的代谢调节。当今生物化学中最具挑战性的问题之一是代谢调节的研究。2.将使用荧光技术对基于发色团的生物聚合物进行表征，以深入了解基团是如何沿着聚合物骨架组装和电子通信的。这项研究将有助于阐明生物聚合物复合材料的结构和设计用于光学和电子加工的新材料。4.研究视黄醇蛋白和细菌视紫红质的分子机制，以了解膜中的光转导。5.脊椎动物胚胎中骨骼肌组织的发育是一个复杂的多步骤过程，目前尚不清楚。荧光分光光度计的灵敏度将被用来解剖成肌细胞膜内的信号转导级联，以了解肌肉细胞的分化。

Trytophan and tyrosine are natural fluorophores and components of proteins. These biological chromophores are fluorescent, i.e., when photo excited they emit light which is characteristic of their chemical and physical environment. Fluorescence is an important analytical technique because of its extreme sensitivity and specificity. The time scale of the fluorescence phenomenon can make the technique a very effective probe of the surroundings of the fluorophore. The requested spectrofluorometer is a state-of-the-art instrument which provides spectral differentiation of fluorophores in a mixture on the basis of difference in fluorescence lifetimes. In the case of a protein molecule, the true emission profile of the tyrosine and tryptophan residues which contribute to the total fluorescence of the protein can be identified and monitored. The spectrofluorometer can also offer information on the molecular size, conformation, and interactions of fluorophores in a protein molecule. With these measurements, the dynamic chemical and physical nature of the fluorophores can be deduced. The biological research projects which require the use of the spectrofluorometer include: 1. The conformation of a metabolic enzyme, ornithine transcarbamoylase, under the influence of a variety of ligands will be analyzed. The goal is to probe the possible metabolic regulation of this enzyme. One of the most challenging problems in biochemistry today is the study of metabolic regulation. 2.The characterization of chromophore-based biopolymers using fluorescence techniques will be conducted to provide insight into how groups are assembled and communicate electronically along a polymer backbone. This study will aid the elucidation of the structure of biological polymer composite and the design of new materials for optical and electronic processing. 4. The molecular mechanism of the retinal based proteins, rhododpsin and bacteriorhodopsin, will be investigated for the understanding of phototransduction in membranes. 5. The development of skeletal muscle tissue in the vertebrate embryo is a complex multistep process which is not yet well understood. The sensitivity of the spectrofluorometer will be exploited to dissect out the signal transduction cascade within the myoblast membrane for the understanding of cell differentiation of muscle.