Description_x000D_ General description_x000D_ Mannitol dehydrogenase (MDH) is a NAD-dependent enzyme, obtained from several organisms like, Lactobacillus brevis, Leuconostoc mesenteroides, Absidia glauca and Rhodococcus. MDH obtained from L. mesenteroides exhibits similarity in sequence with the medium-chain dehydrogenase/reductase protein family. It also contains four identical subunits of about 38 kDa in size._x000D_ The molecular weight of mannitol dehydrogenase is 136 kDa._x000D_ Application_x000D_ Can be used for the production of D-mannitol._x000D_ It has been used in a study to assess glucosylglycerol and glucosylglycerate as enzyme stabilizers._x000D_ This preparation is useful in the determination of mannitol in urine._x000D_ Biochem/physiol Actions_x000D_ Mannitol dehydrogenase (MDH) helps to catalyze the pyridine nucleotide-dependent oxidation of D-mannitol to D-fructose. Mannitol dehydrogenase (MDH) obtained from L. mesenteroides is highly specific for the conversion fructose and mannitol._x000D_ Unit Definition_x000D_ One unit will reduce 1.0 μmole of D-fructose per min in the presence of NADH at pH 5.3 at 30°C. One unit of enzyme, as defined above, is equivalent to approximately 1.8 units of enzyme, as described by Lunn et al., one unit will oxidize 1.0 μmole of D-mannitol per min in the presence of NAD at pH 8.6 at 40°C._x000D_ Physical form_x000D_ Lyophilized powder containing buffer salts, potassium phosphate, and dithiothreitol_x000D_ Preparation Note_x000D_ Partially purified_x000D_ Analysis Note_x000D_ Assayed according to the method of Yamanaka, Meth. Enzymol., 41(B), 138 (1975).