title: Purification and properties of alpha-amino-beta-carboxymuconate-epsilon-semialdehyde decarboxylase (ACMSD), key enzyme of niacin synthesis from tryptophan, from hog kidney.
abstract: alpha-Amino-beta-carboxymuconate-epsilon-semialdehyde decarboxylase (ACMSD) (EC 4.1.1.45) was purified to a homogeneous state from hog kidney cytosol by ammonium sulfate fractionation, Butyl-Toyopearl 650, hydroxyapatite, DEAE-Sephadex, Toyopearl HW55, Superdex 200 and TSK-gel G3000SW chromatographies. The molecular weight of the enzyme was estimated to be 58,000 by TSK-gel G3000SW gel filtration. The optimum pH (constant concentration) was 7.5. The Km for alpha-amino-beta-carboxymuconate-epsilon-semialdehyde was 1.61 x 10(-5) M. The activity of purified enzyme was inhibited by some chemical modifying reagents such as monoiodoacetic acid and p-(chloromercuri) benzoic acid. A sulfhydryl group was deduced to exist in the active site of the enzyme.
authors.affiliation: Department of Bioproduction Science, Faculty of Horticulture, University of Chiba, Matsudo, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Egashira
authors.forename: H
authors.initials: H
authors.lastname: Kouhashi
authors.forename: T
authors.initials: T
authors.lastname: Ohta
authors.forename: H
authors.initials: H
authors.lastname: Sanada
mesh_terms: D000645:Ammonium Sulfate; D000818:Animals; D002262:Carboxy-Lyases / Q000037:antagonists & inhibitors / Q000302:isolation & purification* / Q000378:metabolism; D002845:Chromatography; D003600:Cytosol / Q000201:enzymology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005590:Fractional Precipitation; D006863:Hydrogen-Ion Concentration; D007668:Kidney / Q000201:enzymology*; D007700:Kinetics; D008970:Molecular Weight; D009525:Niacin / Q000096:biosynthesis*; D013552:Swine; D014364:Tryptophan / Q000378:metabolism*
chemical_list: D004791:Enzyme Inhibitors; D009525:Niacin; D014364:Tryptophan; D002262:Carboxy-Lyases; C024396:aminocarboxymuconate-semialdehyde decarboxylase; D000645:Ammonium Sulfate