KINETICS OF LIGAND-BINDING OF CYTOCHROME OXIDASES - A COMPARATIVE-STUDY

The plethora of microbial oxidases revealed by photochemical action spectra (Chance, B. (1989) Biochim. Biophys. Acta 1000, 345-347) has led to detailed identification, purification and overproduction in many species, to the point where kinetic comparison of properties seems to allow structure/function deductions. This work compares the carbon monoxide recombination of five types of oxidases obtained from various organisms. The results are plotted in an Arrhenius-type plot and suggest that the carbon monoxide ligation is a sensitive indicator of the heme environment specific for an oxidase expressed under a given oxygen concentration. This survey of the carbon monoxide recombination kinetics of naturally occurring cytochrome oxidases in whole cells shows evidence for structural control of the reaction kinetics.