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Water‐mediated conformational transitions in nicotinic receptor M2 helix bundles: a molecular dynamics study
Author(s) -
Ramasubbu Sankararamakrishnan,
Mark S. P. Sansom
Publication year - 1995
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/0014-5793(95)01376-8
Subject(s) - helix bundle , helix (gastropod) , molecular dynamics , molecule , crystallography , chemistry , biophysics , bundle , nicotinic acetylcholine receptor , conformational change , protein subunit , acetylcholine receptor , protein structure , chemical physics , stereochemistry , materials science , receptor , computational chemistry , biochemistry , biology , organic chemistry , ecology , snail , gene , composite material
The ion channel of the nicotinic acetylcholine receptor is a water‐filled pore formed by five M2 helix segments, one from each subunit. Molecular dynamics simulations on bundles of five M2α7 helices surrounding a central column of water and with caps of water molecules at either end of the pore have been used to explore the effects of intrapore water on helix packing. Interactions of water molecules with the N‐terminal polar sidechains lead to a conformational transition from right‐ to left‐handed supercoils during these simulations. These studies reveal that the pore formed by the bundle of M2 helices is flexible. A structural role is proposed for water molecules in determining the geometry of bundles of isolated pore‐forming helices.