title: Differences in substrate specificities of monoamine oxidase A from human liver and placenta.
abstract: The substrate specificities of monoamine oxidase (MAO) A isolated from human placenta and of human liver expressed in yeast have been compared in homogeneous preparations with respect to Vmax and Km values for natural and synthetic substrates and Ki values for competitive inhibitors. MAO A from these two sources is known to differ in at least 5 amino acid residues. While the Km and Ki values were found to be nearly identical in the enzymes from these two sources, the Vmax differed significantly on bulky synthetic substrates.
authors.affiliation: Department of Biochemistry and Biophysics, University of California, San Francisco 94143.
authors.forename: A K
authors.initials: AK
authors.lastname: Tan
authors.forename: W
authors.initials: W
authors.lastname: Weyler
authors.forename: J I
authors.initials: JI
authors.lastname: Salach
authors.forename: T P
authors.initials: TP
authors.lastname: Singer
mesh_terms: D015655:1-Methyl-4-phenylpyridinium / Q000031:analogs & derivatives* / Q000494:pharmacology*; D005260:Female; D006801:Humans; D007527:Isoenzymes / Q000378:metabolism*; D007700:Kinetics; D008099:Liver / Q000201:enzymology*; D008995:Monoamine Oxidase / Q000378:metabolism*; D010920:Placenta / Q000201:enzymology*; D011247:Pregnancy; D013329:Structure-Activity Relationship; D013379:Substrate Specificity
chemical_list: D007527:Isoenzymes; D008995:Monoamine Oxidase; D015655:1-Methyl-4-phenylpyridinium