Development and validation of transferable amide I vibrational frequency maps for peptides.

L Wang, C T Middleton, M T Zanni, J L Skinner

Index: J. Phys. Chem. B 115(13) , 3713-24, (2011)

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Abstract

Infrared (IR) spectroscopy of the amide I band has been widely utilized for the analysis of peptides and proteins. Theoretical modeling of IR spectra of proteins requires an accurate and efficient description of the amide I frequencies. In this paper, amide I frequency maps for protein backbone and side chain groups are developed from experimental spectra and vibrational lifetimes of N-methylacetamide and acetamide in different solvents. The frequency maps, along with established nearest-neighbor frequency shift and coupling schemes, are then applied to a variety of peptides in aqueous solution and reproduce experimental spectra well. The frequency maps are designed to be transferable to different environments; therefore, they can be used for heterogeneous systems, such as membrane proteins.