Identification of quaternary ammonium compounds as potent inhibitors of hERG potassium channels

Quaternary Ammonium Compounds as Water Channel Blockers

From the Department of Physiology, Nijmegen Center for Molecular Life Sciences, Radboud University Nijmegen Medical Center, 6500 HB Nijmegen, Nijmegen, The Netherlands, the Max-Planck Institute for Biophysical Chemistry, Theoretical and Computational Biophysics Department, Am Fassberg, D-37077, Göttingen, Germany, and the Department of Chemistry, University of Edinburgh, Kings Buildings, West M...

Kinetics of Tethering Quaternary Ammonium Compounds to K+ Channels

Polymeric maleimido-quaternary ammonium (QA) compounds have been shown to function as molecular tape measures when covalently tethered to external cysteine residues of a Shaker K(+) channel (Blaustein R.O., P.A. Cole, C. Williams, and C. Miller. 2000. Nat. Struct. Biol. 7:309-311). For sufficiently long compounds, the cysteine-maleimide tethering reaction creates a high concentration, at the ch...

Quaternary ammonium compounds as structural probes of single batrachotoxin-activated Na+ channels

Quaternary ammonium (QA) blockers are well-known structural probes for studying the permeation pathway of voltage-gated K+ channels. In this study we have examined the effects of a series of n-alkyl-trimethylammonium compounds (Cn-QA) on batrachotoxin (BTX)-activated Na+ channels from skeletal muscle incorporated into planar lipid bilayers. We found that these amphipathic QA compounds (Cn-QA wh...

The Electroreduction of Quaternary Ammonium Compounds

Interactions of Quaternary Ammonium Compounds and Proteins

A simple met.hod of titration with a cationic detergent has been developed which permits rapid estimation of the concentration of urinary protein with a minimum of manipulations and time. The method depends on the formation of an insoluble anion-cation complex between quaternary ammonium ions, hereinafter referred to as the cationic detergent, and proteins, in the present instance mainly human ...