TRANSIENT CIRCULAR DICHROISM STUDIES OF PROTEIN MOTIONS

时间分辨圆二色光谱（TRCD）是一种新的 我们在实验室开发的实验技术， 蛋白质构象动力学研究。 该提案提出 利用三氯化碳和四氯化碳进行的生物化学过程的持续研究和新研究， 互补的时间分辨激光光谱。 在赠款期间，与 TRCD技术及其光谱学应用 将研究生物分子中的构象运动。 是 我们的目标是开发收集瞬态紫外线的技术， 圆二色谱 我们的方法的实验细节是 概述。 建议的改善措施将可收集 在205 nm和250 nm之间的紫外圆二色性光谱，在任何 所需的时间延迟在30皮秒和10微秒之间 光激发 光谱的这一区域监测着 蛋白质骨架的吸收。 紫外CD光谱 提供了蛋白质中存在的二级结构的量度， 溶液 对血红素蛋白质的弛豫的继续研究 将进行配体光解离。 在此期间的主要努力 下一个资助期将侧重于使用紫外CD技术，沿着 各种激光光谱探针来检查（a）次级 蛋白质折叠和解折叠中的结构进化和（B） 小多肽中光诱导的螺旋-卷曲转变。 蛋白 折叠是生物化学中的一个重要问题。 的应用 时间分辨UV CD光谱对这个问题提供了产生新的 和令人兴奋的洞察力的时间尺度与形成 蛋白质二级结构 还将进行研究， 开发新的光化学方法来触发蛋白质解折叠 和折叠过程。

Time-resolved circular dichroism (TRCD) spectroscopy is a new experimental technique that we have developed in our laboratory for the study of protein conformational dynamics. This proposal presents continued and new studies of biochemical processes using TRCD and complementary time-resolved laser spectroscopies. During the grant period, both technical developments associated with the TRCD technique and applications of this spectroscopy to the study of conformational motions in biological molecules will be pursued. It is our goal to develop the technology for collecting transient ultraviolet circular dichroism spectra. The experimental details of our approach are outlined. The proposed improvements will enable collection of ultraviolet circular dichroism spectra between 205 nm and 250 nm, at any desired time delay between 30 picoseconds and 10 microseconds following photoexcitation. This region of the optical spectrum monitors the absorption of the protein backbone. CD spectra in the ultraviolet provide a measure of the secondary structures present in proteins in solution. Continued studies on the relaxation of heme proteins following ligand photodissociation will be conducted. The major effort during this next grant period will focus on using the UV CD technique along with a variety of laser spectroscopic probes to examine the (a) secondary structure evolution in the folding and unfolding of proteins and (b) photo-induced helix-coil transitions in small polypeptides. Protein folding is an important problem in biochemistry. The application of time resolved UV CD spectroscopy to this problem offers to produce new and exciting insights into the time scales associated with the formation of protein secondary structure. Research will also be conducted aimed at developing new photochemical methods for triggering protein unfolding and folding processes.