Uridine diphosphoglucose dehydrogenase of pea seedlings

Abstract
Uridine di-phosphoglucose dehydrogenase, an enzyme catalyzing a diphosphopyridine nucleotide-dependent oxidation of uridine diphosphoglucose, was purified about 1000-fold from an extract of germinated pea seedlings. Some of the properties of the purified enzyme were examined. Like its counterpart in liver, the purified enzyme catalyzes a 2-step oxidation of uridine diphosphoglucose but does not oxidize uridine diphosphogalactose. The product of the oxidation was isolated and identified as uridine diphos-phoglucuronic acid. The relationship of this enzymic mechanism to uronic acid metabolism in plants is discussed.