Open AccessPurification and characterization of the malate dehydrogenase from Streptomyces aureofaciens
Author(s) -
Mikulášová Darina,
Kollárová Marta,
MiginiacMaslow Myroslawa,
Decottignies Paulette,
Jacquot JeanPierre,
Kutejová Eva,
Mernik Nataša,
Egyudová Ingrid,
Musrati Rabia,
Horecká Tatiana
Publication year - 1998
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.1574-6968.1998.tb12875.x
Subject(s) - malate dehydrogenase , streptomyces aureofaciens , citrate synthase , molecular mass , biochemistry , biology , enzyme , peptide sequence , amino acid , streptomycetaceae , streptomyces , actinomycetales , bacteria , gene , genetics
The malate dehydrogenase (MDH) from Streptomyces aureofaciens was purified to homogeneity and its physical and biochemical properties were studied. Its amino‐terminal sequence perfectly matched the amino‐terminal sequence of the MDH from Streptomyces atratus whose biochemical characteristics have never been determined. The molecular mass of the native enzyme, estimated by size‐exclusion chromatography, was 70 kDa. The protein was a homodimer, with a 38‐kDa subunit molecular mass. It showed a strong specificity for NADH and was much more efficient for the reduction of oxaloacetate than for the oxidation of malate, with a pH optimum of 8. Unlike MDHs from other sources, it was not inhibited by excess oxaloacetate. This first complete functional characterization of an MDH from Streptomyces shows that the enzyme is very similar in many respects to other bacterial MDHs with the notable exception of a lack of inhibition by excess substrate.