Amino Acids, Proteins and Porphyrins
In cytochrome P 450, P stands for
a. Most of the oxidation reaction of detoxification are catalyzed by monooxygenase or cytochrome P450 (= mixed function oxidase)
b. The usage P450→refers to the absorption peak (at 450 nm), exhibited by the enzyme when exposed to carbon monoxide.
c. They are all hemoproteins, containing heme as the prosthetic group.
d. Cyt. P species are found in the highest concentration in the microsomes of liver (i.e. endoplasmic
e. reticulum). In Adrenal gland they occur in mitochondria as well as in the endoplasmic reticulum.
a. Cyt. P450 is considered the most versatile biocatalyst known. The mechanism of action is dependent upon NADPH.
b. Cyt. P448→ Specific for the metabolism of polycyclic aromatic hydrocarbons, hence known as Aromatic hydrocarbon Hydroxylase.