The hydration of protein secondary structures

The hydration of the main-chain carbonyl (CO) groups in proteins have been studied using infra-red spectroscopy, and computer-graphics analysis of high resolution protein crystal structures. The IR measurements indicate that the strength of water binding to the CO groups is lower in β-sheet proteins compared with α-helical ones. Analysis of the protein crystal structures shows that this is due primarily to differences in the geometry ofwater-CO group interactions in the two types of secondary structure.