FOURIER TRANSFORM INFRARED/RAMAN SPECTROMETER

最先进的傅里叶变换（FT）红外/拉曼光谱仪 将被用来进行生物分子的振动光谱研究。 所选仪器为Digilab FTS 60 A，能够进行步进扫描 从衰减的宽带IR光获得的干涉图 在选定的波长下，通过薄的生物样品，或从近红外 来自1064 nm强激光的光被散射并移位到 通过拉曼效应产生各种更长的波长。 该仪器的步进扫描能力，沿着其快速（400 KHz）数字转换器，具有19位动态范围，将使获得 宽带时间分辨红外吸收和拉曼散射测量 时间分辨率可达5 μ s。此外，使用高分辨率 重复频率调Q Nd+-YAG激光器应具有时间分辨率 对于低至10毫微秒范围的拉曼实验。 分束器和检测器组合将沿着获得 光谱仪将允许10，000 -100厘米的完整光谱覆盖， 红外线，和斯托克斯位移拉曼带的测量， 4000 - 75厘米。FTS 60 A的显微镜附件将允许敏感的 红外吸收差测量将在微量的 样品（1 ng）。 美国国立卫生研究院支持的核心小组正计划使用光谱仪 主要是研究生物膜的结构和动力学 组件，包括简单的脂质双层系统，支持平面 双层与小肽结合，和中等大的膜 重组成脂质囊泡的蛋白质。 拟议的核心用户有 所有独立发表的NIH支持的论文都证明了 在使用FT-IR和/或拉曼光谱， 回答有关膜组件的结构问题， 各种生物医学上重要的过程，如视觉传导， 跨膜氯离子转运与流感病毒插入细胞 膜。

A state=of-the-art- Fourier-transform (FT) infrared/Raman spectrometer will be used o perform vibrational spectroscopic studies of biomolecules. The instrument selected, a Digilab FTS60A, is capable of step-scanning interferograms obtained either from broadband IR light that is attenuated at selected wavelengths by a thin biological sample, or from near-IR light from an intense 1064-nm laser that is scattered and shifted to a variety of longer wavelengths via the Raman effect. The step-scanning capability of the instrument, along with its fast (400 KHz) digitizer with 19-bit dynamic range, will make it possible to obtain broadband time-resolved IR absorption and Raman scattering measurements with time resolution as fast as 5-mus. Furthermore, using a high- repetition-rate Q-switched Nd+-YAG laser should permit time resolution for Raman experiments down into the 10 nsec range. The beamsplitter and detector combination to be obtained along with spectrometer will allow complete spectral coverage from 10,000-100 cm in the infrared, and of measurements of Stokes-shifted Raman bands from 4,000-75cm. A microscope accessory for the FTS60A will allow sensitive IR absorbance difference measurements to be made on tiny quantities of sample (1 ng). The NIH-supported core group is planning to use the spectrometer principally to examine the structure and dynamics of biomembrane components, including simple lipid bilayer systems, supported planar bilayers with small peptides bound to them, and moderately large membrane proteins reconstituted into lipid vesicles. The proposed core users have all independently published NIH-supported papers demonstrating a capability and interest in using FT-IR and/or Raman spectroscopy to answer structural questions about membrane components involved in a variety of biomedically-important processes such as visual transduction, transmembrane chloride transport, and influenza virus insertion into cell membranes.