Vigano C, Manciu L, Buyse F, Goormaghtigh E, Ruysschaert J M
Laboratoire de Chimie Physique de Macromolécules aux Interfaces, Université Libre de Bruxelles, 1050 Bruxelles, Belgium.
Biopolymers. 2000;55(5):373-80. doi: 10.1002/1097-0282(2000)55:5<373::AID-BIP1011>3.0.CO;2-U.
During the last few years, attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR) has become one of the most powerful methods to determine the structure of biological materials and in particular of components of biological membranes, like proteins that cannot be studied by x-ray crystallography and NMR. ATR-FTIR requires a little amount of material (1-100 microg) and spectra are recorded in a matter of minutes. The environment of the molecules can be modulated so that their conformation can be studied as a function of temperature, pressure, pH, as well as in the presence of specific ligands. For instance, replacement of amide hydrogen by deuterium is extremely sensitive to environmental changes and the kinetics of exchange can be used to detect tertiary conformational changes in the protein structure. Moreover, in addition to the conformational parameters that can be deduced from the shape of the infrared spectra, the orientation of various parts of the molecule can be estimated with polarized IR. This allows more precise analysis of the general architecture of the membrane molecules within the biological membranes. The present review focuses on ATR-IR as an experimental approach of special interest for the study of the structure, orientation, and tertiary structure changes in peptides and membrane proteins.
在过去几年中，衰减全反射傅里叶变换红外光谱法（ATR - FTIR）已成为确定生物材料结构，尤其是生物膜成分结构的最强大方法之一，这些生物膜成分如蛋白质，无法通过X射线晶体学和核磁共振进行研究。ATR - FTIR所需材料量少（1 - 100微克），几分钟内即可记录光谱。分子环境可以调节，从而可以研究其构象随温度、压力、pH值以及特定配体存在情况的变化。例如，用氘取代酰胺氢对环境变化极为敏感，交换动力学可用于检测蛋白质结构中的三级构象变化。此外，除了可从红外光谱形状推导的构象参数外，还可以用偏振红外光估计分子各部分的取向。这使得能够更精确地分析生物膜内膜分子的总体结构。本综述重点介绍ATR - IR，它是一种特别适用于研究肽和膜蛋白的结构、取向及三级结构变化的实验方法。
