title: D-(+)-lactate dehydrogenase from Lactobacillus murinus.
abstract: D-(+)-Lactate dehydrogenase from Lactobacillus murinus was purified 670-fold. The Mr was 140,000 as determined by gel filtration. Maximum enzymatic activity was observed at 25 degrees C and pH 6.0 in 200 mM Na2KPO4 buffer. When the temperature was increased from 60 to 65 degrees C, the enzyme was completely inactive in 5 min. The apparent Km for pyruvate and NADH were 4.7 x 10(-4) and 1 x 10(-5) M, respectively. Pyruvate analogs such as oxalate, oxamate, 2-oxobutyrate, and malonate acted as a competitive inhibitors. L-Lactate and L-malate were noncompetitive inhibitors.
mesh_terms: D001426:Bacterial Proteins / Q000037:antagonists & inhibitors / Q000302:isolation & purification* / Q000378:metabolism; D006358:Hot Temperature; D006863:Hydrogen-Ion Concentration; D007770:L-Lactate Dehydrogenase / Q000037:antagonists & inhibitors / Q000302:isolation & purification* / Q000378:metabolism; D007778:Lactobacillus / Q000201:enzymology*; D013379:Substrate Specificity
chemical_list: D001426:Bacterial Proteins; D007770:L-Lactate Dehydrogenase