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Biophys J. 2003 Apr;84(4):2331-7.

Simulation of MscL gating in a bilayer under stress.

Author information

1
Istituto di Chimica del Riconoscimento Molecolare, CNR, 20131 Milan, Italy. colombo@icrm.cnr.it

Abstract

The initial stages of the gating of the mechanoselective channel of large conductance from Mycobacterium tuberculosis have been studied in atomic detail using molecular dynamics simulation techniques. A truncated form of the protein complex embedded in a palmitoyloleoylphosphatidylcholine lipid bilayer and surrounded by explicit water was simulated under different pressure conditions to mimic the effects of tension and compression within the membrane on the protein. As a direct result of lateral tension being applied to the membrane, an increase in the tilt of a subset of the transmembrane helices was observed. This in turn led to the enlargement of the pore and the disruption of the hydrophobic gate consisting of residues Ile-14 and Val-21. The simulations suggest that opening occurs in a sequential staged process. Such a mechanism could explain the partial opening or staged conductance observed in patch-clamp experiments using related large conductance mechanosensitive channel complexes.

PMID:
12668441
PMCID:
PMC1302799
DOI:
10.1016/S0006-3495(03)75038-3
[Indexed for MEDLINE]
Free PMC Article

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