hide
Free keywords:
MAS solid-state NMR; Magic Angle Spinning; Perdeuteration; Proton detection; TOBSY; Side-chain assignment; Micro-crystalline proteins
Abstract:
Proteins with excessive deuteration give access to proton detected solid-state NMR spectra of extraordinary resolution and sensitivity. The high spectral quality achieved after partial proton back-exchange has been shown to start a new era for backbone assignment, protein structure elucidation, characterization of protein dynamics, and access to protein parts undergoing motion. The large absence of protons at non-exchangeable sites, however, poses a serious hurdle for characterization of side chains, which play an important role especially for structural understanding of the protein core and the investigation of protein–protein and protein–ligand interactions, e.g. This has caused the perdeuteration approach to almost exclusively be amenable to backbone characterization only. In this work it is shown that a combination of isotropic 13C mixing with long-range 1H/13C magnetization transfers can be used effectively to also access complete sets of side-chain chemical shifts in perdeuterated proteins and correlate these with the protein backbone with high unambiguity and resolution. COmbined POlarization from long-Range transfers And Direct Excitation (COPORADE) allows this strategy to yield complete sets of aliphatic amino acid resonances with reasonable sensitivity.
