FTIR spectroscopy has long been used as a tool used to gain average structural information on proteins. With the advent of stable isotope editing, FTIR can be used to derive accurate information on isolated amino acids. In particular, in an anisotropic sample such as membrane layers, it is possible to measure the orientation of the peptidic carbonyl groups. Herein, we review the theory that enables one to obtain accurate restraints from FTIR spectroscopy, alongside considerations for sample suitability and general applicability. We also propose approaches that may be used to generate structural models of simple membrane proteins based on FTIR orientational restraints. This article is part of a Special Issue entitled: FTIR in membrane proteins and peptide studies.
Bibliographical noteFunding Information:
This work was supported in part by grants from the National Institutes of Health ( R21AI064797 ), the Israeli Science Foundation ( 784/01 , 1249/05 , 1581/08 ) and the Horowitz Foundation . ITA is the Arthur Lejwa Professor of Structural Biochemistry at the Hebrew University of Jerusalem.
- Isotope editing
- Membrane protein
- Molecular modeling