D-threo-aldose 1-dehydrogenase

In enzymology, d-threo-aldose 1-dehydrogenase^[1] is an enzyme that catalyzes the chemical reaction

d-threo-aldose + NAD⁺ ${\displaystyle \rightleftharpoons }$ d-threo-aldono-1,5-lactone + NADH + H⁺

Thus, the two substrates of this enzyme are d-threo-aldose and NAD⁺, whereas its 3 products are d-threo-aldono-1,5-lactone, NADH, and H⁺.

This enzyme belongs to the family of oxidoreductases, specifically those acting on the CH-OH group of donor with NAD⁺ or NADP⁺ as acceptor. The systematic name of this enzyme class is d-threo-aldose:NAD⁺ 1-oxidoreductase. Other names in common use include l-fucose dehydrogenase, (2S,3R)-aldose dehydrogenase, dehydrogenase, l-fucose, and l-fucose (d-arabinose) dehydrogenase. This enzyme participates in ascorbate and aldarate metabolism.

d-threo-aldose 1-dehydrogenase is capable of oxidizing l-glucose, l-xylose, d-arabinose, and l-fucose, allowing Trinickia caryophylli, the organism from which it was first isolated, to use l-Glucose as a source of energy. Oxidation of these monosaccharides is inhibited by their respective enantiomers.^[2]