Direct Detection of ~(3h)J_(NC) Hydrogen-Bond Scalar Couplings in Proteins by Solid-State NMR Spectroscopy

摘要

Hydrogen bonds (H-bonds) are important and ubiquitous interactions in chemistry and biology. They are a key element in proteins and nucleic acids for stabilizing the three-dimensional fold and are thus important for the functionality. The presence of an H-bond can be indirectly deduced from the local geometry as obtained from X-ray or NMR methods, and a variety of NMR parameters depend also on hydrogen bonding (e.g. chemical shifts induced by H-bonds or ~2H quadrupolar coupling constants). Direct evidence of hydrogen bonding, however, is provided by the presence of an H-bond-mediated scalar coupling.