1. Purification and Characterization of NADPH-dependent 2-Oxoaldehyde Reductase from Parsley
- Author
-
Fumitaka Hayase, Hiromichi Kato, Zhi Qun Liang, and Toshihide Nishimura
- Subjects
chemistry.chemical_classification ,biology ,Chemistry ,Dimer ,Kinetics ,Methylglyoxal ,Reductase ,Enzyme assay ,General Biochemistry, Genetics and Molecular Biology ,Catalysis ,Maillard reaction ,symbols.namesake ,chemistry.chemical_compound ,Enzyme ,Biochemistry ,symbols ,biology.protein ,General Agricultural and Biological Sciences - Abstract
A NADPH-dependent 2-oxoaldehyde reductase, which catalyzes the reduction of 3-deoxyglucosone to 3-deoxyfructose and reduction of methylglyoxal to acetol, was isolated and purified from parsley leaves. 2-Oxoaldehyde compounds were found to be specially good substrates and monocarbonyl compounds were poor substrates for this reductase. The optimum pH of the enzyme activity was 7.0–7.5. The Km for 3-deoxyglucosone and methylglyoxal were 15 mm and 13 mm, respectively. The molecular weight of the enzyme was estimated to be 67,000 and the enzyme is proposed to be a dimer composed of identical subunits (MW = 35,000). The enzyme activity was completely inhibited by p-chloromercuribenzoate. The reaction catalyzed by the enzyme was virtually irreversible. The changes in methylglyoxal and NADPH by the enzyme were stoichiometrically equivalent.
- Published
- 1990