Open AccessProperties of d ‐lactate dehydrogenase from Lactobacillus bulgaricus : a possible different evolutionary origin for the d ‐ and l ‐lactate dehydrogenases
Author(s) -
Bras Gisèle,
Garel JeanRenaud
Publication year - 1991
Publication title -
fems microbiology letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.899
H-Index - 151
eISSN - 1574-6968
pISSN - 0378-1097
DOI - 10.1111/j.1574-6968.1991.tb04510.x
Subject(s) - lactate dehydrogenase , dehydrogenase , biochemistry , nad+ kinase , lactobacillus , dimer , enzyme , biology , lactic acid , chemistry , stereochemistry , bacteria , fermentation , genetics , organic chemistry
Summary 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 K m values of 50 μM 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, Mn 2+ 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 lactate dehydrogenase from L. bulgaricus could not be evolutionarily related to the family of NAD‐dependent l ‐lactate dehydrogenases.