Water orientation and dynamics in the closed and open influenza B virus M2 proton channels.

Autor: Gelenter MD; Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA, USA., Mandala VS; Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA, USA., Niesen MJM; Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA, USA., Sharon DA; Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA, USA., Dregni AJ; Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA, USA., Willard AP; Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA, USA., Hong M; Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA, USA. meihong@mit.edu.
Jazyk: angličtina
Zdroj: Communications biology [Commun Biol] 2021 Mar 12; Vol. 4 (1), pp. 338. Date of Electronic Publication: 2021 Mar 12.
DOI: 10.1038/s42003-021-01847-2
Abstrakt: The influenza B M2 protein forms a water-filled tetrameric channel to conduct protons across the lipid membrane. To understand how channel water mediates proton transport, we have investigated the water orientation and dynamics using solid-state NMR spectroscopy and molecular dynamics (MD) simulations. 13 C-detected water 1 H NMR relaxation times indicate that water has faster rotational motion in the low-pH open channel than in the high-pH closed channel. Despite this faster dynamics, the open-channel water shows higher orientational order, as manifested by larger motionally-averaged 1 H chemical shift anisotropies. MD simulations indicate that this order is induced by the cationic proton-selective histidine at low pH. Furthermore, the water network has fewer hydrogen-bonding bottlenecks in the open state than in the closed state. Thus, faster dynamics and higher orientational order of water molecules in the open channel establish the water network structure that is necessary for proton hopping.
Databáze: MEDLINE