N-METHYLCARBAZOLE METABOLISM: A PROBE FOR CHARACTERIZING THE MULTIPLE FORMS OF CYTOCHROME P-450

Abstract

Publisher Summary This chapter describes a probe for characterizing the multiple forms of cytochrome P-450. N–methylcarbazole (NMC) is metabolized by rabbit liver microsomes to four monohydroxylated products: (1) NHMC, (2) 1–OH–NMC, (3) 2–OH–NMC, and (4) 3–OH–NMC. The formation of several different metabolites from a single substrate by liver microsomes has been observed with several substrates and has been attributed to the presence of different forms of cytochrome P-450 in the microsomal fraction. Several different forms of cytochrome P-450 have been isolated from rabbit liver microsomes, and each of these forms exhibits a unique substrate specificity and regiospecificity for a single substrate. The metabolism of NMC to multiple products may be useful in monitoring the activity of different forms of cytochrome P-450 in hepatic microsomes and in further characterizing the catalytic specificity of the purified forms of cytochrome P-450.