@article{8e481dd9e47848ad9aeba9cdd3d4e693,
title = "Instantaneous ion configurations in the K+ion channel selectivity filter revealed by 2D IR spectroscopy",
abstract = "Potassium channels are responsible for the selective permeation of K ions across cell membranes. K+ ions permeate in single file through the selectivity filter, a narrow pore lined by backbone carbonyls that compose four K+ binding sites Here we report on the two-dimensional infrared (2D IR) spectra of a semisynthetic KcsA channel with sitespecific heavy (13C18O) isotope labels in the selectivity filter The ultrafast time resolution of 2D IR spectroscopy provides an instantaneous snapshot of the multi-ion configurations and structural distributions that occur spontaneously in the filter Two elongated features are resolved revealing the statistical weighting of two structural conformations The spectra are reproduced by molecular dynamics simulations of structures with water separating two K+ions in the binding sites ruling out configurations with ions occupying adjacent sites.",
author = "Kratochvil, {Huong T.} and Carr, {Joshua K.} and Kimberly Matulef and Annen, {Alvin W.} and Hui Li and Micha{\l} Maj and Jared Ostmeyer and Serrano, {Arnaldo L.} and H. Raghuraman and Moran, {Sean D.} and Skinner, {J. L.} and Eduardo Perozo and Beno{\^i}t Roux and Valiyaveetil, {Francis I.} and Zanni, {Martin T.}",
note = "Funding Information: This research was supported by U.S. National Institutes of Health grant NIH DK79895 (H.T.K., A.L.S., S.D.M., M.M., and M.T.Z), the University of Wisconsin Foundation (J.K.C. and J.L.S.), NIH R01-GM062342 (H.L. and B.R.), NIH GM087546 (K.M., A.W.A., and F.I.V.), NIH R01-GM057846 (E.P. and H.R), and the Membrane Protein Structural Dynamics Consortium U54 GM087519. F.I.V. and A.W.A. thank members of the Xiao group for advice on chemical synthesis. M.T.Z. is an owner of PhaseTech Spectroscopy, Inc. Additional materials, methods, and supplementary text detailing the data reported in this paper can be found in the supplementary materials.",
year = "2016",
month = sep,
day = "2",
doi = "10.1126/science.aag1447",
language = "English (US)",
volume = "353",
pages = "1040--1044",
journal = "Science",
issn = "0036-8075",
publisher = "American Association for the Advancement of Science",
number = "6303",
}