Estimation of amino acid residue side‐chain absorption in the infrared spectra of protein solutions in heavy water

Abstract The values of maximum frequencies, intensities, and other spectral parameters of the main absorption bands of amino acid residue side‐chain groups have been obtained in the 1500–1800‐cm −1 region for solutions in heavy water at pD 1–12. It is shown that absorption of residues of asparagine, glutamine, aspartic and glutamic acids, arginine, and tyrosine must be taken into account in quantitative studies of the infrared spectra of polypeptide and protein solutions in heavy water. Examples of separating out the amide I band for ribonuclease A in heavy water are given.