PARTIAL PURIFICATION AND CHARACTERIZATION OF SORBITOL DEHYDROGENASE FROM RAT BRAIN1

Abstract— Sorbitol dehydrogenase (EC 1.1.1.14) was isolated and purified 700‐fold from rat brain. Most substrate specificities and properties are similar to those reported for sorbitol dehydrogenase from other mammalian tissues; however, the substrate specificity of this brain enzyme does not conform to the d‐cis 2,4 dihydroxy configuration. The physiological substrate for sorbitol dehydrogenase is probably sorbitol. The isolation of sorbitol dehydrogenase from rat brain tissue is confirmation that (1) all the constituents of the sorbitol (polyol) pathway are present in the brain and that (2) fructose synthesis from glucose in this tissue proceeds via the intermediate formation of sorbitol.