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。 所选的仪器是Digilab FTS60A，能够分步扫描 从衰减的宽带红外光获得的干涉图 用薄的生物样品或从近红外在选定的波长 来自1064 nm强激光的光被散射并移位到 通过拉曼效应产生的各种较长波长。 该仪器的步进扫描能力以及它的FAST(400 KHz)具有19位动态范围的数字化仪，将使其能够获得 宽带时间分辨红外吸收和拉曼散射测量 时间分辨率高达5微秒。此外，使用高- 重复率调Q的Nd~+-YAG激光器应具有时间分辨率 用于低至10毫微秒范围的拉曼实验。 分束器和探测器的组合将与 光谱仪将允许从10,000-100厘米的完整光谱覆盖 红外和测量斯托克斯移位的拉曼光谱 4000-75厘米。FTS60A的显微镜附件将允许敏感度 红外吸收差测量将对微量的 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 主要研究生物膜的结构和动力学 组件，包括简单的脂类双层系统，支撑平面 结合了小肽的双层膜和中等大小的膜 重组成脂泡的蛋白质。建议的核心用户有 所有独立发表的由美国国立卫生研究院资助的论文都展示了 使用FT-IR和/或拉曼光谱的能力和兴趣 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， 跨膜氯转运和流感病毒进入细胞 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.