Ca2+-dependent interaction of BAPTA with phospholipids.
Starting from a comparative study of different Ca2+ chelators on the G-protein-induced inhibition of the CaV2.1 Ca channels, we demonstrate that BAPTA and DM-nitrophen are able to interact, in a Ca2+- and lipid-dependent manner, with phospholipid monolayers. Critical insertion pressure and sensitivity to charged lipids indicated that insertion in the lipid film may occur in biological membranes as those found on Xenopus oocytes. This novel property is not found for EGTA and EDTA and may participate to the unusual ability of BAPTA-related molecules to chelate Ca2+ ions in the very close vicinity of the plasma membrane, where most of the Ca2+-dependent signalling triggered by voltage-gated Ca2+ currents occurs.
Rousset
M
M
CRBM, CNRS FRE2593, 1919 Route de Mende, 34293 Montpellier, France.
Cens
T
T
Vanmau
N
N
Charnet
P
P
D000085:Acetates / Q000494:pharmacology; D000818:Animals; D002118:Calcium / Q000378:metabolism*; D015220:Calcium Channels / Q000187:drug effects; D002614:Chelating Agents / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D004533:Egtazic Acid / Q000031:analogs & derivatives* / Q000378:metabolism* / Q000494:pharmacology; D005029:Ethylenediamines / Q000494:pharmacology; D015640:Ion Channel Gating / Q000187:drug effects; D008564:Membrane Potentials / Q000187:drug effects; D008839:Microelectrodes; D008845:Microinjections; D009865:Oocytes / Q000187:drug effects; D018408:Patch-Clamp Techniques; D010743:Phospholipids / Q000378:metabolism*; D014982:Xenopus laevis
D000085:Acetates; D015220:Calcium Channels; D002614:Chelating Agents; D005029:Ethylenediamines; D010743:Phospholipids; C057014:DM-nitrophen; D004533:Egtazic Acid; C025603:1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid; D002118:Calcium