Isoenzymes of the Glycolytic and Pentose Phosphate Pathways in Proplastids from the Developing Endosperm of Ricinis communis L.

Abstract

Two isoenzymes each of hexose-P [phosphate] isomerase, aldolase and 6-P-gluconate dehydrogenase were found in the endosperm of developing castor beans (R. communis L.). One isoenzyme for each activity is present in the proplastic fraction. Only one form of glucose-6-P dehydrogenase was found. Apparently the partition of an enzyme activity between cytosol and plastid is regulated by the synthesis of isoenzymes which are subcellular site specific. The use of diethylaminoethyl-Sephadex A-25 sievorptive chromatography for the preparation of plant enzymes is described.