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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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References

[1] Lear, J.D., Wasserman, Z.R., and DeGrado, W.F., Science 240, 11771181 (1988).Google Scholar
[2] Woolf, T.B., and Roux, B., Proc. Natl. Acad. Sci. USA. 91, 1163111635 (1994).Google Scholar
[3] Elber, R., Chen, D.P., Rojewska, D., and Eisenberg, R., Biophys. J. 68, 906924 (1995).Google Scholar
[4] Pullman, A., Chem. Rev. 91, 793812 (1991).Google Scholar
[5] Sansom, M.S.P.. Sankararamakrishnan, H.S.S.R., Kerr, I.D., and Breed, J., Biophys. J. 68, 12951310 (1995).Google Scholar
[6] Martyna, G.J., Tuckerman, M., Tobias, D.J., and Klein, M.L., Mol. Phys. 87, 11171157 (1996).Google Scholar
[7] Jorgensen, W.L., Chandresekhar, J., Madura, J.D., Impey, R.W., and Klein, M.L., J. Chem. Phys. 79, 926935 (1983).Google Scholar
[8] Tuckerman, M.. Berne, B.J.. and Martyna, G.J., J. Chem. Phys. 97, 19902001 (1992).Google Scholar
[9] Siepmann, J.I.. Karaborni, S., and Smit, B., Nature 365, 330332 (1993).Google Scholar
[10] Brooks, B.R., Bruccoleri, R.E., Olafson, B.D., States, D.J., Swaminathan, S., and Karplus, M., J. Comp. Chem. 4, 187217 (1983).Google Scholar
[11] Zhong, Q.F., Jiang, Q., Moore, P.B., Newns, D.M., and Klein, M.L., to be appeared in Biophys. J. 74, (1998).Google Scholar