Binding, aniline-cytochrome

B. Testa, Chem.—Biol. Interact., 34, 287 (1981). Structural and Electronic Factors Influencing the Inhibition of Aniline Hydroxylation by Alcohols and Their Binding to Cytochrome P-450. 

Testa, B. (1981), Structural and electronic factors influencing the inhibition of aniline hydroxylation by alcohols and their binding to cytochrome P-450. Chem. Biol. Interact. 34, 287-300. 

The carcinogenicity of af la toxin is reduced by protein deficiency, presumably because of reduced metabolic activation to the epoxide intermediate, which may be the ultimate carcinogen, which binds to DNA (Fig. 5.14). A deficiency in dietary fatty acids also decreases the activity of the microsomal enzymes. Thus, ethylmorphine, hexobarbital, and aniline metabolism are decreased, possibly because lipid is required for cytochromes P-450. Thus, a deficiency of essential fatty acids leads to a decline in both cytochromes P-450 levels and activity in vivo. 

Cytochrome c peroxidase (CCP) catalyzes the oxidation of ferrocytochrome c (cyt c). Many site-directed mutagenesis studies have been performed on this enzyme in efforts to better understand and rationally engineer heme peroxidase function [149 -156], Various studies indicate that the large protein substrate cyt c binds to CCP in a different region than smaller substrates [155, 157]. Whereas small substrates such as phenol and aniline are believed to approach the heme from its distal side and bind at the heme edge, cyt c lies much further from the heme, and electron transfer seems to occur from the proximal side [158], The low activity and selectivity exhibited by CCP compared to HRP and CPO is attributed to the limited access by small substrates to the heme [159]. 

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