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

by Ingolfsson, H. I.; Koeppe, R. E.; Andersen, O. 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).

Journal
FEBS Letters
Volume
585
Issue
19
Year
2011
Start Page
3101-3105
URL
https://dx.doi.org/10.1016/j.febslet.2011.08.040
ISBN/ISSN
1873-3468; 0014-5793
DOI
10.1016/j.febslet.2011.08.040