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.
- FEBS Letters
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- 1873-3468; 0014-5793