Thermodynamics and kinetics of the glyoxylate cycle.
Because the standard Gibbs energies of formation of all the species of reactants in the glyoxylate cycle are known at 298.15 K, it is possible to calculate the apparent equilibrium constants of the five reactions in the cycle in the pH range 5-9 and ionic strengths from 0 to approximately 0.35 M. In making calculations on such a system, it is convenient to specify concentrations of coenzymes like NADox and NADred because they are involved in many reactions and may be in steady states. Calculations are given for [NADox] = 1000[NADred] and [NADox] = 10[NADred]. Equilibrium compositions are calculated using computer programs when all the reactants are present initially and when only glyoxylate and CoA are present initially. The kinetics of the reactions in the glyoxylate cycle at specified concentrations of NADox and NADred are calculated by numerical solution of the steady-state rate equations for the case where the reactant concentrations are below their Michaelis constants and only glyoxylate and CoA are present initially.
Alberty
Robert A
RA
Department of Chemistry, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, USA. alberty@mit.edu
D000105:Acetyl Coenzyme A / Q000737:chemistry / Q000378:metabolism; D002384:Catalysis; D006038:Glyoxylates / Q000737:chemistry* / Q000378:metabolism*; D007700:Kinetics; D008293:Malates / Q000737:chemistry / Q000378:metabolism; D008956:Models, Chemical; D009243:NAD / Q000737:chemistry / Q000378:metabolism; D009994:Osmolar Concentration; D010084:Oxidation-Reduction; D012984:Software; D019802:Succinic Acid / Q000737:chemistry / Q000378:metabolism; D013816:Thermodynamics; D013997:Time Factors
D006038:Glyoxylates; D008293:Malates; D009243:NAD; D000105:Acetyl Coenzyme A; C030298:malic acid; D019802:Succinic Acid; C031150:glyoxylic acid