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A Phenomenological Model of the LS2 Ion Channel

Published online by Cambridge University Press:  15 February 2011

Qingfeng Zhong
Affiliation:
Center for Molecular Modeling and Department of Chemistry, University of Pennsylvania, Philadelphia, PA 19104-6323
Dennis M. Newns
Affiliation:
Thomas J. Watson Research Center, International Business Machines Corporation, Yorktown Heights, NY 10598
Michael L. Klein
Affiliation:
Center for Molecular Modeling and Department of Chemistry, University of Pennsylvania, Philadelphia, PA 19104-6323
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Abstract

A molecular dynamics simulation has been performed on a synthetic membrane-spanning ion channel, consisting of four α-helical peptides, each of which is composed of the sequence Ac-(LSLLLSL)3-CONH2. In the present simulation, the channel was initially assembled dynamically as a parallel bundle in the octane portion of a phase separated water/octane system, which provided a membrane-mimetic environment, without imposing any structural constraints. After more than one nanosecond, the four helices were found to adopt an associated dimer state with two-fold symmetry, which after a further 3 ns evolved to a coiled-coil tetrameric structure with a left-handed twist. Based on the simulation, we proposed a phenomenological model to describe the two-states of the channel.

Type
Research Article
Copyright
Copyright © Materials Research Society 1998

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