title: Expression of functional human monoamine oxidase A and B cDNAs in mammalian cells.
abstract: Monoamine oxidase (MAO) A and B are important enzymes that metabolize biogenic amines throughout the body. Previous studies had suggested that both MAO A and B consist of two subunits of molecular masses of 63 and 60 kilodaltons, respectively. The cDNAs encoding one subunit of human liver MAO A and B have been expressed in mammalian cells by transfection of the individual clones. The proteins expressed from these cDNAs are shown to be catalytically active. Similar to the endogenous enzymes, the expressed MAO A prefers serotonin as a substrate and is sensitive to the inhibitor clorgyline. In contrast, the expressed MAO B prefers phenylethylamine as a substrate and is sensitive to the inhibitor deprenyl. These results suggest that a single polypeptide of MAO A (or B), existing as either a monomer or homodimer, is enzymatically active. The ability to obtain functional MAO A and B from their respective cDNA clones allows us to study further the structure and function relationships of these important enzymes.
authors.affiliation: Division of Biological Sciences, School of Pharmacy, University of Southern California, Los Angeles 90033.
authors.forename: N C
authors.initials: NC
authors.lastname: Lan
authors.forename: C H
authors.initials: CH
authors.lastname: Chen
authors.forename: J C
authors.initials: JC
authors.lastname: Shih
mesh_terms: D002460:Cell Line; D003010:Clorgyline / Q000494:pharmacology; D004247:DNA / Q000235:genetics*; D006801:Humans; D007527:Isoenzymes / Q000235:genetics / Q000378:metabolism; D008099:Liver / Q000201:enzymology; D008995:Monoamine Oxidase / Q000235:genetics* / Q000378:metabolism; D008996:Monoamine Oxidase Inhibitors; D010627:Phenethylamines / Q000378:metabolism; D012642:Selegiline / Q000494:pharmacology; D012701:Serotonin / Q000378:metabolism; D013379:Substrate Specificity; D014162:Transfection
chemical_list: D007527:Isoenzymes; D008996:Monoamine Oxidase Inhibitors; D010627:Phenethylamines; D012642:Selegiline; C029261:phenethylamine; D012701:Serotonin; D004247:DNA; D008995:Monoamine Oxidase; D003010:Clorgyline