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Water and potassium dynamics inside the KcsA K + channel
Author(s) -
Guidoni Leonardo,
Torre Vincent,
Carloni Paolo
Publication year - 2000
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/s0014-5793(00)01712-9
Subject(s) - kcsa potassium channel , potassium channel , potassium , chemistry , ion , molecular dynamics , chemical physics , molecule , biophysics , analytical chemistry (journal) , ion channel , computational chemistry , biochemistry , chromatography , receptor , organic chemistry , biology
Molecular dynamics simulations and electrostatic modeling are used to investigate structural and dynamical properties of the potassium ions and of water molecules inside the KcsA channel immersed in a membrane‐mimetic environment. Two potassium ions, initially located in the selectivity filter binding sites, maintain their position during 2 ns of dynamics. A third potassium ion is very mobile in the water‐filled cavity. The protein appears engineered so as to polarize water molecules inside the channel cavity. The resulting water induced dipole and the positively charged potassium ion within the cavity are the key ingredients for stabilizing the two K + ions in the binding sites. These two ions experience single file movements upon removal of the potassium in the cavity, confirming the role of the latter in ion transport through the channel.