Site-specific protein methyl deuterium quadrupolar patterns by proton-detected 3D H-C-H MAS NMR spectroscopy.

Determination of protein structure and dynamics is key to understand the mechanism of protein action. Perdeuterated proteins have been used to obtain high resolution/sensitivty NMR experiments via proton-detection. These methods utilizes H, C and N nuclei for chemical shift dispersion or relaxation probes, despite the existing abundant deuterons. However, a high-sensitivity NMR method to utilize deuterons and e.g. determine site-specific deuterium quadrupolar pattern information has been lacking due to technical difficulties associated with deuterium's large quadrupolar couplings. Here, we present a novel deuterium-excited and proton-detected three-dimensional H-C-H MAS NMR experiment to utilize deuterons and to obtain site-specific methyl H quadrupolar patterns on detuterated proteins for the first time. A high-resolution fingerprint H-N HSQC-spectrum is correlated with the anisotropic deuterium quadrupolar tensor in the third dimension. Results from a model perdeuterated protein has been shown.