Inhibition of recombinant aldose-6-phosphate reductase from peach leaves by hexose-phosphates, inorganic phosphate and oxidants

HARTMAN, MATÍAS D. (IGUAL CONTRIBUCIÓN); FIGUEROA, CARLOS M. (IGUAL CONTRIBUCIÓN); ARIAS, DIEGO G.; IGLESIAS, ALBERTO A.

PLANT AND CELL PHYSIOLOGY

OXFORD UNIV PRESS

Lugar: Oxford; Año: 2017 vol. 58 p. 145 - 155

0032-0781

Glucitol,also known as sorbitol, is a major photosynthetic product in plants from theRosaceae family. This sugar alcohol is synthesized from glucose-6-phosphate bythe combined activities of aldose-6-phosphate reductase (Ald6PRase) andglucitol-6-phosphatase. In this work we show the purification andcharacterization of recombinant Ald6PRase from peach leaves. The recombinantenzyme was inhibited by glucose-1-phosphate, fructose-6-phosphate,fructose-1,6-bisphosphate and orthophosphate. Oxidizing agents irreversiblyinhibited the enzyme and produced protein precipitation. Enzyme thiolation withoxidized glutathione protected the enzyme from insolubilization caused bydiamide, while incubation with NADP+ (one of the substrates) completelyprevented enzyme precipitation. Our results suggest that Ald6PRase is finelyregulated to control carbon partitioning in peach leaves.