Enzyme Activity Measurement for Mannitol 2-Dehydrogenase Using Spectrophotometric Assays

Creative Enzymes is capable of providing the reliable and stable activity assay of mannitol 2-dehydrogenase, based on decades of experiences in enzyme methodology. With our strong expertise in enzyme research and development, we will provide you top-quality activity tests and technical services.

Mannitol 2-dehydrogenases (EC1.1.1.67; MDH) are the enzymes that catalyze the NAD⁺/NADP⁺-dependent reversible oxidation of D-mannitol or D-mannitol-1-phosphate to D-fructose or D-fructose 6-phosphate. The systematic name of this enzyme class is D-mannitol: NAD⁺ 2-oxidoreductase, which is also known as mannitol dehydrogenase and D-mannitol dehydrogenase. They have been broadly used in agriculture, pharmaceutical, and chemical industries. The enzyme is a secondary alcohol dehydrogenase, which selectively acts on polyhydroxylated compounds with the C2(R) configuration. Broad attentions have been focused on the enzyme because of the potential applications in chiral synthesis. Recently, mannitol 2-dehydrogenase was found existing in plants with the function of converting D-mannitol to D-mannose. These mannitol 2-dehydrogenases from plants belong to the medium-chain zinc-containing dehydrogenase family, different from the other mannitol 2-dehydrogenases from fungi, which belong to the short-chain dehydrogenase family. As an oxidoreductase, Mannitol 2-dehydrogenase catalyzes the CH-OH group of the substrate and uses NAD⁺ or NADP⁺ as the cofactor.

Mannitol 2-dehydrogenases play an important role in mannitol cycle, which is essential for fructose and mannose metabolism. They participate in the second half cycle involving the conversion of mannitol to turn D-fructose back to fructose 6-phosphate. D-mannitol is formed in the mannitol cycle from fructose 6-phosphate with two enzymatic steps: the direct reduction of fructose 6-phosphate into D-mannitol 1-phosphate, and the hydrolysis of the phosphoric ester of the latter to produce D-mannitol. Among all ten hexitols, D-mannitol is one of the only three hexitols which occur naturally. Due to its favorable bulking properties, D-mannitol is extensively used in food and pharmaceutical industries. It is worthy noting that it does not cause tooth decay and is also safe for diabetics. For all these advantages, mannitol 2-dehydrogenases are getting more and more attentions, but the activity assays of mannitol 2-dehydrogenases have not been well established using spectrophotometric analysis. Creative Enzymes has been optimizing and updating the most advanced technology in the spectrophotometric analysis for mannitol 2-dehydrogenases. Therefore, we commit to offering our clients a portfolio of sustainable, versatile, and customized solutions by expanding our innovation capacity and strengthening our technical service.

Figure: The crystal structure of P. fluorescens mannitol 2-dehydrogenases.
Reference: Kathryn L. Kavanagh et al. J Biol Chem. 2002 Nov 8;277(45):43433-42.