Difference absorption spectrum of cytochrome c oxidase in the presence of acephate ( N-acetvl O, S-dimethyl thiophosphoramide)

The α-peak in the difference spectrum between reduced cytochrome c oxidase (cytochrome a and a 3) plus acephate (pH 9.5) and oxidized enzyme, shifted from 605 nm to 592 nm. The difference spectrum between reduced cytochrome c oxidase plus acephate (pH 9.5) and the reduced enzyme showed that the α and γ peaks shifted to 592 nm and 432 nm, respectively. The effect of acephate on the spectrum of the reduced cytochrome c oxidase is similar to that of carbon monoxide.