Phase II Enzymes
Phase 2 enzymes in principle are part of the cellular biotransformation machinery. Cellular biotransformation of xenobiotics and endobiotics, including carcinogens, may be divided into three sequential phases: phase 1 (oxidation, reduction, and hydrolysis reactions), phase 2 (conjugation reactions), and phase 3 (further modification and transport by efflux transporters). Phase 2 enzymes traditionally refer to the enzymes that catalyze the conjugation reactions of various substrates with endogenous ligands, such as glutathione S-transferase (GST), UDP-glucuronosyltransferase (UGT), N-acetyltransferase (NAT), and sulfotransferase (SULT). However, the term has gradually become broader in scope as it has also been used by an increasing number of investigators for a number of enzymes that catalyze phase 1 reactions, such as...
KeywordsEpoxide Hydrolase Antioxidant Response Element Nrf2 Activation Cellular Antioxidant Capacity Light Subunit
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