RT Journal Article SR Electronic T1 N-Oxygenation of Clozapine by Flavin-Containing Monooxygenase JF Drug Metabolism and Disposition JO Drug Metab Dispos FD American Society for Pharmacology and Experimental Therapeutics SP 524 OP 527 VO 25 IS 4 A1 Meera Tugnait A1 Edward M. Hawes A1 Gordon McKay A1 Allan E. Rettie A1 Robert L. Haining A1 Kamal K. Midha YR 1997 UL http://dmd.aspetjournals.org/content/25/4/524.abstract AB The involvement of FMO in the N-oxygenation of CLZ was investigated by use of purified FMOs and human liver microsomes that contained the mean amount of immunoreactive FMO3 relative to other human liver microsomal preparations in a liver bank. In the microsomal preparation the involvement of FMO was indicated through enzyme inhibition by methimazole, heat inactivation, and protection against heat inactivation by NADPH. Also the Michaelis-Menten kinetic constant;KM determined for CLZ N-oxidation catalyzed by purified human FMO3 (324 μM) was very similar to the mean value obtained in these laboratories for the microsomal preparations of seven human livers. The American Society for Pharmacology and Experimental Therapeutics