Effects of green tea catechins on gramicidin channel function and inferred changes in bilayer properties

by Ingolfsson, Helgi I.; Koeppe II, R. Erdman; Andersen, Olaf S.

Green tea's health benefits have been attributed to its major polyphenols, the catechins: (-)-epigal-locatechin gallate (EGCG), (-)-epicatechin gallate (ECG), (-)-epigallocatechin (EGC), and epicatechin (EC). Catechins (especially EGCG) modulate a wide range of biologically important molecules, including many membrane proteins. Yet, little is known about their mechanism(s) of action. We tested the catechins' bilayer-modifying potency using gramicidin A (gA) channels as molecular force probes. All the catechins alter gA channel function and modify bilayer properties, with a 500-fold range in potency (EGCG > ECG >> EGC > EC). Additionally, the gallate group causes current block, as evident by brief downward current transitions (flickers). (C) 2011 Federation of European Biochemical Societies. Published by Elsevier B. V. All rights reserved.

Journal
FEBS Letters
Volume
585
Issue
19
Year
2011
Start Page
3101
ISBN/ISSN
1873-3468; 0014-5793
PMID
21896274
DOI
10.1016/j.febslet.2011.08.040