Protein Structure in KBr Pellets by Infrared Spectroscopy

Fourier Transform Infrared Spectrometric Analysis of Protein Conformation: Effect of Sampling Method and Stress Factors

“…Recently, Griebenow et al reviewed the arguments to support that the observed spectral changes are mainly caused by changes in the secondary structure and are not caused by water removal per se (37). However, this issue is still under debate and hypotheses stating that no conformational changes occur have also appeared in the literature (25,26,35). For example, spectral changes in the amide I band of lyophilized lysozyme were interpreted as solely the result of water removal, and this hypothesis correlated well with the other techniques used by the authors (38).…”

“…Also, differences between spectra of protein samples in the solution and solid states have been attributed entirely to changes in secondary structure by some (16 -18, 23, 24), whereas others relate these changes in the spectra solely to the removal of water (25,26). To address some of these issues, we have carried out studies on several proteins, comparing their structure in the solid and solution states under a variety of conditions.…”

Formation of Protein–Birnessite Complex: XRD, FTIR, and AFM Analysis

“…The use of KBr pellets does not affect the protein integrity (23). More recent study of numerous proteins by FTIR showed a better correlation for the secondary structure, using KBr pellets, than that obtained for the protein in solution (24). The cell containing the samples was flushed with N 2 gas for 10 min before scanning to remove atmospheric water vapor and CO 2 from the spectrophotometer.…”

A Holistic Approach for Protein Secondary Structure Estimation from Infrared Spectra in H2O Solutions

“…These methods include, but are not limited to, solitary use or combinations of factor analysis (FA) (16 -20), singular value decomposition (SVD) (21,22), Fourier self-deconvolution (FSD; or resolution enhancement) (14,(23)(24)(25)(26), second derivative (SD) band identification and fitting (27)(28)(29), and the development of spectral correlation coefficients (30,31). Recent reviews of these techniques by Pelton and McLean (32) and Jackson and Mantsch (33) are instructive.…”