Integral membrane proteins in nanodiscs can be studied by solution NMR spectroscopy.
We present a two-dimensional solution NMR spectrum of an integral membrane protein (IMP) in a nanodisc. Solution NMR relies on rapid isotropic tumbling of the analyte with correlation times in the nanosecond range. IMPs in a cellular membrane do not satisfy this condition. Previous liquid-state NMR studies on IMPs were conducted in organic solvent or artificial membrane mimicking particles like detergent micelles. Nanodiscs are relatively small (150 kDa), detergent-free model membranes that are suitable for functional reconstitution of IMPs. Nanodiscs allow solubilization of integral membrane proteins in a nearly native lipid bilayer environment. The 70 residue polypeptide CD4mut was incorporated into nanodiscs. CD4mut features one transmembrane helix. The aliphatic (1)H-(13)C HSQC spectrum of nanodiscs with inserted, ((13)C, (15)N)-labeled CD4mut exhibits reasonably dispersed protein and lipid NMR signals. Our results demonstrate that IMPs in nanodiscs are amenable to liquid-state NMR methodology.
Glück
Julian M
JM
Institute of Structural Biology and Biophysics (ISB-3), Research Centre Jülich, D-52425 Jülich, Germany.
Wittlich
Marc
M
Feuerstein
Sophie
S
Hoffmann
Silke
S
Willbold
Dieter
D
Koenig
Bernd W
BW
D015704:CD4 Antigens / Q000737:chemistry / Q000235:genetics; D006801:Humans; D009682:Magnetic Resonance Spectroscopy; D008565:Membrane Proteins / Q000737:chemistry* / Q000235:genetics; D008567:Membranes, Artificial; D049329:Nanostructures / Q000737:chemistry*; D012996:Solutions
D015704:CD4 Antigens; D008565:Membrane Proteins; D008567:Membranes, Artificial; D012996:Solutions