The binding of cytochrome c peroxidase and ferricytochrome c. A spectrophotometric determination of the equilibrium association constant as a function of ionic strength.
Complex formation between cytochrome c peroxidase and ferricytochrome c perturbs the optical absorption spectrum in the Soret band by about 2%. This perturbation can be utilized as a measure of the complex formed in solution and permits the determination of the stoichiometry and the equilibrium association constant for this reaction. At pH 6, in cacodylate/KNO3 buffers, only a 1:1 complex between cytochrome c peroxidase and ferricytochrome c is detected. The equilibrium association constant for the complex has been determined as a function of ionic strength and varies between (6.0 +/- 3.6) x 10(6) M-1 and (2.2 +/- 1.9) x 10(6) M-1 over the ionic strength range 0.01 M to 0.20 M.
D000818:Animals; D003574:Cytochrome c Group / Q000378:metabolism*; D003578:Cytochrome-c Peroxidase / Q000378:metabolism*; D006321:Heart; D006736:Horses; D009994:Osmolar Concentration; D010544:Peroxidases / Q000378:metabolism*; D012441:Saccharomyces cerevisiae / Q000201:enzymology; D013053:Spectrophotometry
D003574:Cytochrome c Group; D010544:Peroxidases; D003578:Cytochrome-c Peroxidase