title: Effects of green tea catechins on gramicidin channel function and inferred changes in bilayer properties.
abstract: Green tea's health benefits have been attributed to its major polyphenols, the catechins: (-)-epigallocatechin 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).
authors: Department of Physiology and Biophysics, Weill Cornell Medical College, New York, NY 10065, United States. hei2001@med.cornell.edu
authors: Helgi I
authors: HI
authors: Ingólfsson
authors: Roger E
authors: RE
authors: Koeppe
authors: Olaf S
authors: OS
authors: Andersen
mesh_terms: D000975:Antioxidants / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology; D002392:Catechin / Q000031:analogs & derivatives* / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology*; D006096:Gramicidin / Q000378:metabolism; D006801:Humans; D015640:Ion Channel Gating / Q000187:drug effects*; D007473:Ion Channels / Q000235:genetics / Q000378:metabolism*; D008051:Lipid Bilayers / Q000737:chemistry / Q000378:metabolism; D015394:Molecular Structure; D013662:Tea / Q000737:chemistry
chemical_list: D000975:Antioxidants; D007473:Ion Channels; D008051:Lipid Bilayers; D013662:Tea; D006096:Gramicidin; D002392:Catechin; C062669:epicatechin gallate; C045651:epigallocatechin gallate; C057580:gallocatechol