Shapiro D B, Goldbeck R A, Che D, Esquerra R M, Paquette S J, Kliger D S
Department of Chemistry and Biochemistry, University of California at Santa Cruz 95064.
Biophys J. 1995 Jan;68(1):326-34. doi: 10.1016/S0006-3495(95)80191-8.
A standard technique for static optical rotatory dispersion (ORD) measurements is adapted to the measurement of ORD changes on a nanosecond (ns) time scale, giving approximately a million-fold improvement in time-resolution over conventional instrumentation. The technique described here is similar in principle to a technique recently developed for ns time-resolved circular dichroism (TRCD) spectroscopy, although the time-resolved optical rotatory dispersion (TRORD) technique requires fewer optical components. As with static ORD, TRORD measurements may be interpreted by empirical comparisons or may be transformed, via the Kramers-Kronig relations, to more easily interpreted TRCD spectra. TRORD can offer experimental advantages over TRCD in studying kinetic processes effecting changes in the chiral structures of biological molecules. In particular, the wider dispersion of ORD bands compared with the corresponding CD bands means that ORD information may often be obtained outside of absorption bands, a signal-to-noise advantage for multichannel measurements. Demonstration of the technique by its application to ns TRORD and the transform-calculated TRCD of carboxy-hemoglobin (Hb-CO) after laser photolysis is presented.
一种用于静态旋光色散（ORD）测量的标准技术被应用于纳秒（ns）时间尺度上ORD变化的测量，与传统仪器相比，时间分辨率提高了约一百万倍。这里描述的技术在原理上与最近开发的用于纳秒时间分辨圆二色性（TRCD）光谱的技术相似，尽管时间分辨旋光色散（TRORD）技术所需的光学组件更少。与静态ORD一样，TRORD测量可以通过经验比较来解释，也可以通过克拉默斯 - 克朗尼格关系进行变换，以更轻松地解释TRCD光谱。在研究影响生物分子手性结构变化的动力学过程中，TRORD相对于TRCD可以提供实验优势。特别是，与相应的CD带相比，ORD带的色散更宽，这意味着ORD信息通常可以在吸收带之外获得，这对于多通道测量是一个信噪比优势。本文展示了该技术在激光光解后羧基血红蛋白（Hb - CO）的纳秒TRORD和变换计算的TRCD中的应用。
