Construction and Evaluation of a Step Scanning Interferometric Instrument for the Observation of Infrared Circular Dichroism

下面的建议旨在开发一个原型仪器，用于观测红外，或振动圆二色性（VCD），使用步进扫描傅里叶变换（SS-FT）方法。VCD是20世纪70年代中期发展起来的一种光谱学技术，它通过振动跃迁观察到左右圆偏振红外光的微分吸收。这种效应非常小，但却包含了任何其他光谱方法都无法轻易获得的构象和结构信息。商用观测仪器的缺乏限制了VCD作为结构工具的广泛应用。该方案旨在生产新一代VCD仪器，可作为商用VCD光谱仪的蓝图。所提出的仪器被认为是一个VCD光谱仪，而不是一个傅立叶变换红外光谱仪，其中添加了VCD功能。一些技术创新将使该仪器非常独特，并将扩展其能力超出目前VCD光谱的限制。申请人的实验室一直处于振动光学活性发展的前沿，在色散和干涉光谱方法方面具有丰富的经验。因此，该实验室非常适合在新一代VCD光谱仪的开发中发挥主导作用。申请人研究的主要内容是确定生物模型系统的溶液构象：多肽和小蛋白质，以及寡核苷酸及其与药物的相互作用。本文介绍的SS- FT-VCD仪器将在这些研究中使用，以进一步减少VCD数据采集时间，提高光谱质量，并允许从更稀的水溶液中收集光谱。

The following proposal is aimed at developing a prototype instrument for the observation of infrared, or vibrational Circular Dichroism (VCD), using Step-Scanning Fourier transform (SS-FT) methodology. VCD is a spectroscopic technique, developed originally in the mid 1970's, in which the differential absorption of left and right circularly polarized indrared light by vibrational transitions is observed. This effect is very small, yet contains conformational and structural information which cannot be obtained easily by any other spectroscopic method. The lack of commercial instrumentation for its observation has restricted the wider application of VCD as a structural tool. This proposal is intended to produce a new generation of VCD instruments which could serve as blueprints for commercial VCD spectrometers. The proposed instrument is conceived as a VCD spectrometer, rather than a Fourier Transform infrared spectrometer to which VCD capabilities were added. A number of technical innovations will make this instrument very unique, and will extend its capabilities beyond the present limits of VCD spectroscopy. The applicant's laboratory has been in the forefront of the development of vibrational optical activity, and has extensive experience with both dispersive and interferomatic spectroscopic methods. Thus, this laboratory is ideally suited to take a leading role in development of a new generation of VCD spectrometers. The main thrust of the applicant's research is the determination of the solution conformation of biological model systems: peptides and small proteins, as well asoligonucleotides and their interactions with drugs. The SS- FT-VCD instrument described here will be used in these studies to further reduce VCD data acquisition time, improve spectral quality and permit spectra to be collected from more dilute aqueous solutions.