Membrane proteins play an important role in many biological functions. Solid-state NMR spectroscopy is uniquely suited for studying the structure and dynamics of membrane proteins in a membranous environment. The major challenge to obtain high quality solid-state NMR spectra of membrane proteins is sensitivity, due to limited quantities of labeled high-molecular-weight proteins. Here we demonstrate the incorporation of paramagnetic metal (Cu 2+) ions, through either ethylenediaminetetraacetic acid (EDTA) or a chelator lipid, into membrane protein samples for rapid data collection under fast magic-angle spinning (MAS) and low power 1H decoupling. Spectral sensitivity of DsbB (20 kDa), an integral membrane protein, more than doubles in the same experimental time due to 1H T1 relaxation enhancement by Cu2+ ions, with DsbB native fold and active site intact. This technique can be implemented to acquire multidimensional solid-state NMR spectra for chemical shift assignments and structure elucidation of large membrane proteins with small sample quantities.
ASJC Scopus subject areas
- Materials Science(all)
- Physical and Theoretical Chemistry