Study of cytochrome oxidase co-binding site using low-temperature flash photolysis.
Flash photolysis has been used to study the kinetics of CO-binding to the heme alpha isolated cytochrome oxidase. Experiments performed over the range 185-295 degrees K with various CO concentrations have revealed significant deviations from the Arrhenius relationship between rate and temperature. These findings can be explained by a model in which the heme site is considered to have three regions between which CO can move; only from the innermost one can binding to the heme iron take place. The relative enthalpies and entropies of the three regions are calculated.
D000818:Animals; D001665:Binding Sites; D002151:Calorimetry; D002248:Carbon Monoxide; D002417:Cattle; D003576:Electron Transport Complex IV; D007700:Kinetics; D008433:Mathematics; D009206:Myocardium / Q000201:enzymology; D010782:Photolysis; D011485:Protein Binding; D011487:Protein Conformation; D013696:Temperature; D013816:Thermodynamics
D002248:Carbon Monoxide; D003576:Electron Transport Complex IV