| Method |
In order to vary delta GATP the cell interior was dialysed with patch pipette solutions containing 10 mM ATP and different concentrations of ADP and inorganic phosphate. The media were composed to produce delta GATP levels of about -58, -49 and -39 kJ mol-1. ?G(hydrolysis) was calculated from ?G(hydrolysis)=?G°(hydrolysis)+ R×T×ln[ATP]/([ADP]×[Pi]). where ?G(ATP) denotes the standard free energy of ATP
hydrolysis. [ATP], [ADP] and [Pi] represent the respective
concentrations of adenosine triphosphate, adenosine diphosphate
and inorganiic phosphate in the patch pipette media. R and T
have their usual meaning. |