Fourier Deconvolution of the Amide I Raman Band of Proteins as Related to Conformation

Fourier deconvolution has been employed to enhance the resolution of the amide I Raman band of nine proteins found in milk and/or other foods. The broad band was resolved into several components. The overall shape of the amide I Raman band of proteins was found to be nearly Gaussian or to be composed of Gaussian components. A Gaussian function was therefore used for deconvolution. The results obtained were more detailed than those obtained with the Lorentzian approximation usually employed. The resolved band components were assigned to specific protein conformations. The frequencies and assignments are in good agreement with previous Raman work based on entirely different procedures. The band areas of the resolved components appear to reflect the fraction of any given conformation in a protein. Semiquantitative estimations of protein conformation are in reasonable agreement with data obtained by x-ray diffraction and by infrared methods.