Properties of Purified Methylmalonate Semialdehyde Dehydrogenase of Pseudomonas aeruginosa

摘要: Abstract Methylmalonate semialdehyde dehydrogenase, an inducible enzyme from Pseudomonas aeruginosa which catalyzes the oxidation of methylmalonate to propionyl coenzyme A, was purified extent that a preparation obtained homogenous by criterion disc gel electrophoresis. The molecular weight native estimated be 132,000 filtration. dehydrogenase dissociated into subunits in urea or sodium dodecyl sulfate solutions. subunit at between 58,000 and 69,000 techniques electrophoresis filtration sulfate, respectively, means is composed least two subunits. catalyzed reduction NAD with propionaldehyde. In presence CoA, propionyl-CoA product oxidation. active when mercaptoethanol replaced CoA derivative formed then as well. stoichiometry NADH 1:1. 3-Hydroxyisobutyrate 3-hydroxyisobutyrate-1-14C were used generate semialdehyde-1-14C, radioactive carbon dioxide produced present reaction mixture. Michaelis constants for semialdehyde, NAD, mercaptoethanol, propionaldehyde determined. proposal made physiological role cell metabolism catalyze catabolism valine.