Enzymes of the pentose phosphate pathway in the mung-bean seedling

Abstract

The occurrence in extracts of germinating mung-bean seedling of the following enzymes of the oxidative pentose phosphate pathway has been shown: phosphoglucose dehydrogenase, phrsphogluconate dehydro-genase, phosphoribose isomerase, phosphoribulose epimerase, transketolase, transaldolase and phosphoglucose isomerase. During the initial period of germination (up to 48 hours) the amounts and specific activities of the dehydrogenases increase with time. After 72 hours, however, both start decreasing and after 96 hours the enzymes disappear from the extracts. The enzyme phosphoglucose dehydrogenase has been purified partially and its properties have been found to be similar to those of the yeast enzyme. The enzyme is triphosphopyridine nucleotide-specific, and has been successfully used in the assay of glucose 6-phosphate.