The intramolecular autoglucosylation of monomeric glycogenin

SOLEDAD BAZÁN*, FEDERICO M. ISSOGLIO*, MARÍA E. CARRIZO AND JUAN A. CURTINO1

Elsevier

Año: 2008 vol. 371 p. 328 - 328

p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt; LINE-HEIGHT: 200%; TEXT-ALIGN: justify">The ability of monomeric glycogenin to autoglucosylate by an intramolecular mechanism of reaction is described using non glucosylated and partially glucosylated recombinant glycogenin. We determined that monomer glycogenin exists in solution at concentration below 0.60-0.85 µM. The specific autoglucosylation rate of non glucosylated and glucosylated monomeric glycogenin represented fifty and seventy per cent of the specific rate of the corresponding dimeric glycogenin species. The incorporation of a unique sugar unit into the tyrosine hydroxyl group of non glucosylated glycogenin, analyzed by autoxylosylation, occurred at a lower rate than the incorporation into the glucose hydroxyl group of the glucosylated enzyme. The intramonomer autoglucosylation mechanism here described for the first time, confers