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Proton Transfer and Protein Conformation Dynamics in Photosensitive Proteins by Time-resolved Step-scan Fourier-transform Infrared Spectroscopy
Published on: June 27, 2014
Charge-state resolved mid-infrared spectroscopy of a gas-phase protein
Jos Oomens1, Nick Polfer, David T Moore
1FOM Institute for Plasma Physics Rijnhuizen, Edisonbaan 14, NL-3439 MN Nieuwegein, The Netherlands.
Abstract:
Infrared spectra of a 104 amino-acid protein in the gas phase as a function of its charge state are presented. The spectra contain clearly resolvable bands in the amide I and II spectral regions, as well as a band at 1483 cm(-1), which is not observed in solution phase spectroscopy and is especially prominent for the higher charge states. Compared to solution, the amide I band is blue-shifted and the amide II band red-shifted, as expected for species in an environment with reduced hydrogen bonding. The band positions are suggestive of a mostly alpha-helical structure of the protein and their widths are comparable to those in solution, suggesting a similar conformational distribution.
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