For life science research only. Not for use in diagnostic procedures. Sorbitol Dehydrogenase (SDH) Polyol dehydrogenase from sheep liver L-Iditol: NAD 5´-oxidoreductase, EC 1.1.1.14 Cat. No. 10 109 339 001 10 mg (60 mg lyo.) y Version 06 Content version: June 2019 Store at +2 to +8°C Product overview • In the colorimetric assay6 of sorbitol and xylitol, high concentrations of reducing substances Ն ␮ Formulation Lyophilizate (12 mg contain 2 mg enzyme protein and ( 5 g/assay) such as ascorbic acid (in fruit juice) 10 mg maltose; 60 mg contain 10 mg enzyme protein or SO2 (in jam) interfere. A procedure for removing and 50 mg maltose). these reducing substances (with H2O2 and alkali) is given in reference6. Contaminants ADH < 0.01%, GIDH < 0.02%, glucose dehydrogenase < 0.02%, Analysis Information LDH < 0.05%, MDH < 0.05% Quality Control Mr 115,000 SDH Substrate Sorbitol dehydrogenase (SDH) will oxidize D-sorbitol to D-fructose + NADH + H+ D-sorbitol + specificity, relative fructose (Km = 0.7 mM; relative rate = 1.00). The + NAD rates and Km enzyme will also oxidize many other polyols, including L-iditiol to L-sorbose (rate = 0.96), xylitol to D-xylulose (rate = 0.85), ribitol to D-ribulose (rate = 0.49) and Unit definition One unit (U) sorbitol dehydrogenase will reduce allitol to allulose (rate = 0.45). SDH also catalyzes the 1 ␮mol of D-fructose in 1 min at 25° C and pH 7.6 reverse (reduction) reactions of each of the above. The [triethanolamine buffer; 150 mM fructose (non- Km for fructose is 250-300 mM. SDH is specific for saturating concentration)]. The above assay consumes NAD(H); it will utilize NADP(H) only at a 10- to 100-fold 1 ␮mol of NADH per ␮mol of D-sorbitol formed. reduced rate. The enzyme does not oxidize erythritol, D- or L-arabitol, D-iditol, D-mannitol or inositol. SDH References does not reduce D-tagatose, D-mannoheptulose, D-glucose, DL-glyceraldehyde, pyruvate, 2-oxolutarate or acetaldehyde. 1 Bergmeyer, H.U., Grassl, M. & Walter, H-E (1983) in Methods of Enzymatic Analysis (Bergmeyer, H.U., ed), 3rd Ed, Vol. 2, pp. 309-310, VCH, Weinheim, W. Germany- Specific Activity Approx. 40 U/mg enzyme protein at +25° C with Deerfield Beach, FL. 2 Smith, M.G. (1962) Biochem. J. 83, 135-144. D-fructose as substrate. 3 Gerlach, U. (1983) in Methods of Enzymatic Analysis, Vol 3, pp. 112-117. See reference 1. 4 Beutler, H-O. (1984) in Methods of Enzymatic Analysis, Vol 6, pp. 356-362. pH optimum Oxidation of D-sorbitol at a pH of approx. 9.0-9.5 See reference 1. Reduction of fructose at a pH of 7.4-7.6 5 Beutler, H-O. (1984) in Methods of Enzymatic Analysis, Vol 6, pp. 484-490. Note: The reduction of D-fructose is favored. However, See reference 1. alkaline pH shifts the equilibrium in favor of sorbitol 6 Boehringer Mannheim GmbH. (1983) in Methods of Enzymatic Food Analysis, pp. 43-44 oxidation. Changes to Editorial changes. Activators The reactions (oxidation or reduction) are fastest in previous version Tris- or triethanolamine buffer. Trademarks All third party product names and trademarks are the Inhibitors 4-chloromercuribenzoate (0.1 mM), cysteine (2 mM), property of their respective owners. monoiodoacetate, glutathione, cyanide, EDTA (and other chelators), borate, metal ions Ag+ , Hg2+ , Pb 2+ ). Regulatory For life science research only. Not for use in diagnostic Note: Not inhibited by heparin. Disclaimer procedures. Application Reduces L-iditol to L-sorbose. Also acts on D-glucitol Disclaimer of For patent license limitations for individual products and other closely related sugar alcohols. Allows the License please refer to: List of biochemical reagent products reduction of ketones to polyols (see aldolases for the synthesis of ketoses). Storage and Stable at +2 to +8°C until the expiration date printed on Contact and Support stability the label. As aqueous solution stable at +2 to +8°C for several weeks. To ask questions, solve problems, suggest enhancements and report new Note: Store the lyophylizate dry!. applications, please visit our Online Technical Support Site. Technical Tips • D-sorbitol and xylitol are frequently used as sugar To call, write, fax, or email us, visit sigma-aldrich.com, and select your home substitutes for diabetics. Sorbitol is a moistener and country. Country-specific contact information will be displayed. softener in many foods. • The amount of fructose required to saturate SDH is quite high (approx. 400 mM) and somewhat dependent on the assay buffer. For instance, the saturating concentration of fructose is higher in Tris buffer than in triethanolamine3. • The oxidation of xylitol to xylulose (as well as the oxidation of D-sorbitol) is favored by alkaline pH. Roche Diagnostics GmbH At pH 8.6, in triethanolamine buffer with excess Sandhofer Strasse 116 NADH, SDH will quantitatively oxidize xylitol5. 68305 Mannheim Germany 0619.12233622001 ➅.