Numerical simulation of uni-site and bi-site ATP-hydrolysis catalyzed by the membrane-bound H(+)-ATPase from chloroplasts.
The kinetics of ATP-hydrolysis catalyzed by the H(+)-ATPase from chloroplasts was described by an enzyme kinetic model where either one (uni-site catalysis) or two (bi-site catalysis) sites are operating. Numerical simulations are carried out with the software package LARKIN using measured rate constants as a basis. When the ATP-concentration is increased up to 20 nM (at 20 nM enzyme concentration) a change from uni-site to bi-site catalysis occurs at about 7 nM. The measured effective rate constants change by a factor two. However, the calculated rate constants for the second site are drastically increased.
Labahn
A
A
Biologisches Institut, Universität Stuttgart.
Gräber
P
P
D000255:Adenosine Triphosphate / Q000378:metabolism*; D001665:Binding Sites; D002384:Catalysis; D002736:Chloroplasts / Q000201:enzymology*; D003198:Computer Simulation; D007425:Intracellular Membranes / Q000201:enzymology*; D007700:Kinetics; D008956:Models, Chemical; D006180:Proton-Translocating ATPases / Q000378:metabolism*
D000255:Adenosine Triphosphate; D006180:Proton-Translocating ATPases