Characterization of a novel enzyme, N6-acetyl-L-lysine: 2-oxoglutarate aminotransferase, which catalyses the second step of lysine catabolism in Candida maltosa.
A novel aminotransferase catalyzing the second step of lysine catabolism, the oxidative transamination of the alpha-group of N6-acetyllysine, was identified and characterized in the yeast Candida maltosa. The enzyme was strongly induced in cells grown on L-lysine as sole carbon source. Its activity was specific for both N6-acetyllysine and 2-oxoglutarate. The Km values were 14 mM for the donor, 4 mM for the acceptor and 1.7 microM for pyridoxal-5-phosphate. The enzyme had a maximum activity at pH 8.1 and 32 degrees C. Its molecular mass estimated by sodium dodecyl sulphate-polyacrylamide gel electrophoresis was 55 kDa. Since the native molecular mass determined by gel filtration was 120 kDa, the enzyme is probably a homodimer.
Schmidt
H
H
Institut für Biochemie, Fachrichtung Biologie, Ernst-Moritz-Arndt-Universität Greifswald, Germany.
Bode
R
R
D002175:Candida / Q000201:enzymology* / Q000254:growth & development; D002850:Chromatography, Gel; D004591:Electrophoresis, Polyacrylamide Gel; D006863:Hydrogen-Ion Concentration; D007656:Ketoglutaric Acids / Q000378:metabolism; D007700:Kinetics; D008239:Lysine / Q000031:analogs & derivatives* / Q000378:metabolism*; D008970:Molecular Weight; D000637:Transaminases / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism*
D007656:Ketoglutaric Acids; C016949:N-epsilon-acetyllysine; D000637:Transaminases; C079514:N6-acetyl-beta-lysine transaminase; D008239:Lysine