Abstract
Cytochrome P 450s (P450s) are a gene superfamily of heme enzymes involved in xeno-or endo-biotic metabolisms. They have approximately 500 isozymes via evolution, immense diversity in their functions and a broad range of substrate specificities. Thus, they are called diversozymes and their versatility is understood as a mechanism for living via detoxification of toxicants. However, some of the huge human-made chemicals are bioactivated by P 450s. To explain diversity of P 450s, further studies regarding relations between crystal structures and functions of P 450s are required. P 450s can be applied for exposure-biomarkers of environmental pollution, screening of drug metabolism and remedy for pollutants.
