Premium
Matrix Mg 2+ regulates mitochondrial ATP‐dependent potassium channel from heart
Author(s) -
Bednarczyk Piotr,
Dołowy Krzysztof,
Szewczyk Adam
Publication year - 2005
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/j.febslet.2005.01.077
Subject(s) - conductance , potassium channel , biophysics , gating , chemistry , potassium , calcium activated potassium channel , lipid bilayer , membrane potential , magnesium , mitochondrial matrix , cardioprotection , membrane , biochemistry , cytosol , medicine , biology , physics , ischemia , enzyme , organic chemistry , condensed matter physics
Mitochondrial ATP‐regulated potassium (mitoK ATP ) channels play an important role in cardioprotection. Single channel activity was measured after reconstitution of inner mitochondrial membranes from bovine myocardium into a planar lipid bilayer. After incorporation, the potassium channel was recorded with a mean conductance of 103 ± 9 pS. The channel activity was inhibited by ATP/Mg and activated by GDP. Magnesium ions alone affected, in a dose dependent manner, both the channel conductance and the open probability. Magnesium ions regulated the mitoK ATP channel only when added to the trans compartment. We conclude that Mg 2+ regulates the cardiac mitoK ATP channel from the matrix site by affecting both the channel conductance and gating.