PH-dependent conformation, dynamics, and aromatic interaction of the gating tryptophan residue of the influenza M2 proton channel from solid-state NMR.

ABSTRACT: The M2 protein of the influenza virus conducts protons into the virion under external acidic pH. The proton selectivity of the tetrameric channel is controlled by a single histidine (His(37)), whereas channel gating is accomplished by a single tryptophan (Trp(41)) in the transmembrane domain of the protein. Aromatic interaction between these two functional residues has been previously observed in Raman spectra, but atomic-resolution evidence for this interaction remains scarce. Here we use high-resolution solid-state NMR spectroscopy to determine the side-chain conformation and dynamics of Trp(41) in the M2 transmembrane peptide by measuring the Trp chemical shifts, His(37)-Trp(41) distances, and indole dynamics at high and low pH. The interatomic distances constrain the Trp41 side-chain c

SUBMITTER: Williams JK 

PROVIDER: S-EPMC3627873 | biostudies-literature | 2013 Apr

REPOSITORIES: biostudies-literature