Activation pH and Gating Dynamics of Influenza A M2 Proton Channel Revealed by Single-Molecule Spectroscopy.
Angew Chem Int Ed Engl
; 56(19): 5283-5287, 2017 05 02.
Article
em En
| MEDLINE
| ID: mdl-28374543
ABSTRACT
Because of its importance in viral replication, the M2 proton channel of the influenza A virus has been the focus of many studies. Although we now know a great deal about the structural architecture underlying its proton conduction function, we know little about its conformational dynamics, especially those controlling the rate of this action. Herein, we employ a single-molecule fluorescence method to assess the dynamics of the inter-helical channel motion of both full-length M2 and the transmembrane domain of M2. The rate of this motion depends not only on the identity of the channel and membrane composition but also on the pH in a sigmoidal manner. For the full-length M2 channel, the rate is increased from approximately 190â
µs-1 at high pH to approximately 80â
µs-1 at low pH, with a transition midpoint at pHâ
6.1. Because the latter value is within the range reported for the conducting pKa value of the His37 tetrad, we believe that this inter-helical motion accompanies proton conduction.
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Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Termodinâmica
/
Proteínas da Matriz Viral
Idioma:
En
Revista:
Angew Chem Int Ed Engl
Ano de publicação:
2017
Tipo de documento:
Article
País de afiliação:
Estados Unidos