1H-NMR study of gramicidin A transmembrane ion channel. Head-to-head right-handed, single-stranded helices.
The structure of [Val1]gramicidin A incorporated into sodium dodecyl-d25 sulphate micelles has been studied by two-dimensional proton NMR spectroscopy. Analysis of nuclear Overhauser effects, spin-spin couplings and solvent accessibility of NH groups show that the conformation of the Na+ complex of gramicidin A in detergent micelles, which in many ways mimic the phospholipid bilayer of biomembranes, is an N-terminal to N-terminal (head-to-head) dimer (Formula: see text) formed by two right-handed, single-stranded beta 6.3 helices with 6.3 residues per turn, differing from Urry's structure by handedness of the helices.
A S
AS
Arseniev
I L
IL
Barsukov
V F
VF
Bystrov
A L
AL
Lomize
Ovchinnikov YuA
D002942:Circular Dichroism; D004134:Dimyristoylphosphatidylcholine; D006096:Gramicidin; D007473:Ion Channels / Q000378:metabolism*; D009682:Magnetic Resonance Spectroscopy; D008823:Micelles; D008954:Models, Biological; D008958:Models, Molecular; D011487:Protein Conformation; D012967:Sodium Dodecyl Sulfate
D007473:Ion Channels; D008823:Micelles; D006096:Gramicidin; D012967:Sodium Dodecyl Sulfate; D004134:Dimyristoylphosphatidylcholine