pH-induced conformational change of the influenza M2 protein C-terminal domain.
The M2 protein from influenza A is a pH-activated proton channel that plays an essential role in the viral life cycle and serves as a drug target. Using spin labeling EPR spectroscopy, we studied a 38-residue M2 peptide spanning the transmembrane region and its C-terminal extension. We obtained residue-specific environmental parameters under both high- and low-pH conditions for nine consecutive C-terminal sites. The region forms a membrane surface helix at both high and low pH, although the arrangement of the monomers within the tetramer changes with pH. Both electrophysiology and EPR data point to a critical role for residue Lys 49.
Nguyen
Phuong A
PA
Department of Chemistry and Biochemistry, Swarthmore College, Swarthmore, Pennsylvania 19081, USA.
Soto
Cinque S
CS
Polishchuk
Alexei
A
Caputo
Gregory A
GA
Tatko
Chad D
CD
Ma
Chunlong
C
Ohigashi
Yuki
Y
Pinto
Lawrence H
LH
DeGrado
William F
WF
Howard
Kathleen P
KP