Coherent two-dimensional infrared spectroscopy: Quantitative analysis of protein secondary structure in solution

We present a method to quantitatively determine the secondary structure composition of globular proteins using coherent two-dimensional infrared (2DIR) spectroscopy of backbone amide I vibrations (1550–1720 cm−1). Sixteen proteins with known crystal structures were used to construct a library of 2DI...

Full description

Bibliographic Details
Main Authors: Baiz, Carlos R., Peng, Chunte, Reppert, Michael Earl, Jones, Kevin C., Tokmakoff, Andrei
Other Authors: Massachusetts Institute of Technology. Department of Chemistry
Format: Article
Language:en_US
Published: Royal Society of Chemistry 2013
Online Access:http://hdl.handle.net/1721.1/77962
https://orcid.org/0000-0002-7390-3652
Description
Summary:We present a method to quantitatively determine the secondary structure composition of globular proteins using coherent two-dimensional infrared (2DIR) spectroscopy of backbone amide I vibrations (1550–1720 cm−1). Sixteen proteins with known crystal structures were used to construct a library of 2DIR spectra, and the fraction of residues in α-helix, β-sheet, and unassigned conformations was determined by singular value decomposition (SVD) of the measured two-dimensional spectra. The method was benchmarked by removing each individual protein from the set and comparing the composition extracted from 2DIR against the composition determined from the crystal structures. To highlight the increased structural content extracted from 2DIR spectra a similar analysis was also carried out using conventional infrared absorption of the proteins in the library.