Purification and characterization of malate dehydrogenase from Corynebacterium glutamicum

• Published in: Journal of bioscience and bioengineering Vol. 95; no. 6; pp. 562 - 566
• Main Authors: Genda, Tomoko, Nakamatsu, Tsuyoshi, Ozak, Hachiro
• Format: Journal Article
• Language: English
• Published: Japan Elsevier B.V 2003; Elsevier Limited
• Subjects: active center; Brevibacterium flavum; citrate activation; CITRATES; CORYNEBACTERIUM; Corynebacterium glutamicum; MALATE DEHYDROGENASE; PURIFICATION; active center; citrate activation; Brevibacterium flavum; malate dehydrogenase; Corynebacterium glutamicum
• ISSN: 1389-1723; 1347-4421
• DOI: 10.1016/S1389-1723(03)80162-7

The malate dehydrogenase (MDH) (EC 1.1.1.37) from
Corynebacterium glutamicum (
Brevibacterium flavum) ATCC14067 was purified to homogeneity. Its amino-terminal sequence (residues 1 to 8) matched the sequence (residues 2 to 9) of the MDH from C.
glutamicum (GenBank accession no. CAC83073). The molecular mass of the native enzyme was 130 kDa. The protein was a homotetramer, with a 33-kDa subunit molecular mass. The enzyme was almost equally active both for NADU andNADPH as coenzyme on the bases of the
k
cat values at pH 6.5 which is the optimum pH for the both coenzymes. Plotting of the logarithms of the 1/Km, ke, and
k
cat
K
m
values with respect to oxalacetate against pH lead to speculation that imidazolium is possibly a functional group in the active center of the enzyme. Citrate activated the enzyme in the oxidation of malate to oxalacetate and inhibited it in the reverse reaction.