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. 1989 Jul 15;261(2):509–513. doi: 10.1042/bj2610509

Anomeric specificity of D-glucose phosphorylation by rat liver glucose-6-phosphatase.

R Ramirez 1, D Zähner 1, G Marynissen 1, A Sener 1, W J Malaisse 1
PMCID: PMC1138855  PMID: 2549974

Abstract

The anomeric specificity of D-glucose phosphorylation by hepatic glucose-6-phosphatase was examined in rat liver microsomes incubated in the presence of carbamoyl phosphate. At 10 degrees C, the Km for the equilibrated hexose and phosphate donor was close to 56 mM and 11 mM, respectively. The enzymic activity, which was increased in diabetic rats, was about 40% lower in untreated than in sonicated microsomes. No anomeric difference in affinity was found in sonicated microsomes. In untreated microsomes, however, the Km for beta-D-glucose was slightly lower than that for alpha-D-glucose. The maximal velocity was higher with beta- than alpha-D-glucose in both untreated and sonicated microsomes. These data indicate that the phosphotransferase activity of glucose-6-phosphatase cannot account for the higher rate of glycolysis and glycogen synthesis found in hepatocytes exposed to alpha- rather than beta-D-glucose.

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Selected References

These references are in PubMed. This may not be the complete list of references from this article.

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