title: Properties of D-lactate dehydrogenase from Lactobacillus bulgaricus: a possible different evolutionary origin for the D- and L-lactate dehydrogenases.
abstract: The NAD-dependent D-lactate dehydrogenase from Lactobacillus bulgaricus has been purified to homogeneity. This enzyme was a dimer made of two identical chains of molecular mass 37,000. Saturation by either substrate was hyperbolic, with Km values of 50 microM for NADH and 1 mM for pyruvate. The specific activity was 2200 units/mg and was not affected by the presence of fructose-1,6-bisphosphate, Mn2+ ions, ATP or ADP. The amino-terminal sequence determined on 50 residues showed no significant homology with known lactate dehydrogenases, suggesting that the D-lactate dehydrogenase from L. bulgaricus could not be evolutionarily related to the family of NAD-dependent L-lactate dehydrogenases.
authors.affiliation: Laboratoire d'Enzymologie du CNRS, Gif-sur-Yvette, France.
authors.forename: G
authors.initials: G
authors.lastname: Le Bras
authors.forename: J R
authors.initials: JR
authors.lastname: Garel
mesh_terms: D000595:Amino Acid Sequence; D005075:Biological Evolution; D004591:Electrophoresis, Polyacrylamide Gel; D007770:L-Lactate Dehydrogenase / Q000737:chemistry* / Q000302:isolation & purification / Q000378:metabolism; D007778:Lactobacillus / Q000201:enzymology*; D008969:Molecular Sequence Data; D009243:NAD / Q000378:metabolism; D011773:Pyruvates / Q000378:metabolism
chemical_list: D011773:Pyruvates; D009243:NAD; D007770:L-Lactate Dehydrogenase