Ion Channel Permeation: Kinetic Modeling of Ion/Side-Chain Electrostatic Interactions in Native and Fluorinated Gramicidin Channels

Authors

Adam S. Frost, Brigham Young University
David D. Busath, Brigham Young University

Keywords

ion channel permeation, electrostatic interaction, native, fluorinated gramicidin channels

College

Life Sciences

Department

Plant and Wildlife Sciences

Abstract

Gramicidin A is a 15-amino acid peptide produced by several strains of the bacteria Bacillus brevis. The primary sequence of gramicidin A is HCO-L-Val-Gly-L-Ala-D-Leu-L-Ala-D-Val-LVal- D-Val-L-Trp-D-Leu-L-Trp-D-Leu-L-Trp-D-Leu-L-Trp-NHCH2CH2OH. The side-chains alternate chirality, with the odd-numbered residues having the usual L-chirality and the evennumbered residues having D-chirality. The alternating chirality of the side-chains forces them to project away from the lumen of the helix, yielding a tight wind with a central hole formed by the space within the helix. The secondary structure of gramicidin is a single-stranded, left-handed, b6.5-helix that dimerizes head-to-head (N-terminus to N-terminus) in lipid bilayer membranes to form a monovalent, cation-selective channel.1

Recommended Citation

Frost, Adam S. and Busath, David D. (2013) "Ion Channel Permeation: Kinetic Modeling of Ion/Side-Chain Electrostatic Interactions in Native and Fluorinated Gramicidin Channels," Journal of Undergraduate Research: Vol. 2013: Iss. 1, Article 1594.
Available at: https://scholarsarchive.byu.edu/jur/vol2013/iss1/1594