Polyol dehydrogenase that catalyzes the reversible NAD(+)-dependent oxidation of various sugar alcohols. Is active with xylitol, L-iditol and D-sorbitol (D-glucitol) as substrates, leading to the C2-oxidized products D-xylulose, L-sorbose and D-fructose, respectively (By similarity). Is a key enzyme in the polyol pathway that interconverts glucose and fructose via sorbitol, which constitutes an important alternate route for glucose metabolism. May play a role in sperm motility by using sorbitol as an alternative energy source for sperm motility (By similarity).
Subcellular locations: Mitochondrion membrane, Cell projection, Cilium, Flagellum
Associated with mitochondria of the midpiece and near the plasma membrane in the principal piece of the flagellum. Also found in the epididymosome, secreted by the epididymal epithelium and that transfers proteins from the epididymal fluid to the sperm surface.