The objective of the research is to obtain an understanding of the detailed mechanism of cytochrome c peroxidase catalyzed oxidations of a variety of electron donors utilizing hydrogen peroxide. The information obtained will be helpful in determining the function and understanding the mode of action of the peroxidases and of heme-containing enzymes in general. Transient state and steady state kinetics will be employed to elucidate the mechanism under a variety of conditions, in particular, to separate substrate binding and electron transfer processes in the reaction sequence and to establish the factors involved in each. The effect of protein modification on the kinetics will be investigated to determine if specific amino acids are directly involved in the catalytic process. Supplementary studies will include determination of the equilibrium binding properties of cytochrome c and other substrates with cytochrome c peroxidase, determination of the rates of ligand binding to the heme, and pH titration behavior of cytochrome c peroxidase.