Purification of Glycogen Debranching Enzyme from Porcine Brain: Evidence for Glycogen Catabolism in the Brain

  • MAKINO Yasushi
    Department of Chemistry, Graduate School of Science, Osaka Prefecture University
  • OMICHI Kaoru
    Department of Chemistry, Graduate School of Science, Osaka Prefecture University

Search this article

Abstract

Amylo-1,6-glucosidase from porcine brain was purified to homogeneity by ammonium sulfate fractionation, followed by sequential steps of liquid chromatography on DEAE-Sephacel, Sephacryl S-300, and Super Q. The purified enzyme had both maltooligosaccharide transferase and amylo-1,6-glucosidase activities within a single polypeptide chain, and the combination of these two activities removed the branches of phosphorylase limit dextrin. Based on these results, the purified enzyme was identified as a glycogen debranching enzyme (GDE). The molecular weight of the brain GDE was 170,000 by gel-filtration and 165,000 by reducing SDS–PAGE. The pH profile of maltooligosaccharide transferase activity coincided with that of the amylo-1,6-glucosidase activity (pH optimum at 6.0). The existence of GDE as well as glycogen phosphorylase in the brain explains brain glycogenolysis fully and supports the hypothesis that glycogen is a significant source of energy in this organ.

Journal

Citations (4)*help

See more

References(40)*help

See more

Details 詳細情報について

Report a problem

Back to top