Effect of cytochrome C oxidase and polyanions on the alkaline transition of ferricytochrome C.

Application of heparin, polyadenylate, polyglutamate and polygalacturonate resulted in changes in the electron absorption spectrum of cytochrome c that resembled those after cytochrome c oxidase application at neutral pH. The formed complexes of cytochrome c with polyanions retain the bond of Met-80 with heme iron. Cytochrome c oxidase and the polyanions increased the apparent pKa of alkaline transition of cytochrome c by an order of magnitude.