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Publication Abstract from PubMed

The thermostable d-lactate dehydrogenase from Lactobacillus jensenii (Ljd-LDH) is a key enzyme in the production of the d-form of lactic acid from pyruvate concomitant with the oxidation of NADH to NAD(+). The polymers of d-lactic acid are used as biodegradable bioplastics. The crystal structures of Ljd-LDH and in complex with NAD(+) were determined at 2.13 and 2.60A resolutions, respectively. The Ljd-LDH monomer consists of the N-terminal substrate-binding domain and the C-terminal NAD-binding domain. The Ljd-LDH forms a homodimeric structure, and the C-terminal NAD-binding domain mostly enables the dimerization of the enzyme. The NAD cofactor is bound to the GxGxxG NAD-binding motif located between the two domains. Structural comparisons of Ljd-LDH with other d-LDHs reveal that Ljd-LDH has unique amino acid residues at the linker region, which indicates that the open-close dynamics of Ljd-LDH might be different from that of other d-LDHs. Moreover, thermostability experiments showed that the T50(10) value of Ljd-LDH (54.5 degrees C) was much higher than the commercially available d-lactate dehydrogenase (42.7 degrees C). In addition, Ljd-LDH has at least a 7 degrees C higher denaturation temperature compared to commercially available d-LDHs.

Crystal structure and thermodynamic properties of d-lactate dehydrogenase from Lactobacillus jensenii.,Kim S, Gu SA, Kim YH, Kim KJ Int J Biol Macromol. 2014 Jul;68:151-7. doi: 10.1016/j.ijbiomac.2014.04.048. Epub, 2014 Apr 30. PMID:24794195^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.