Anomer specificity of glucose-6-phosphatase and glucokinase.
The anomeric form of glucose produced by glucose-6-phosphatase was studied using an apparatus that specifically measures beta-D-glucose. The time course of beta-D-glucose formation from glucose-6-P by glucose-6-phosphatase is essentially linear. In the presence of mutarotase, this rate is reduced to 70% of that obtained in the absence of mutarotase. When detergent treated microsomes were used, the rate of beta-D-glucose formation is unaffected by mutarotase. These results suggest that only beta-anomer of glucose is produced by microsomal glucose-6-phosphatase and this specificity is determined by translocase for glucose-6-P or glucose. It was also demonstrated that alpha-D-glucose is the substrate for glucokinase.
D000818:Animals; D002238:Carbohydrate Epimerases / Q000494:pharmacology; D005941:Glucokinase / Q000378:metabolism*; D005947:Glucose / Q000378:metabolism; D005952:Glucose-6-Phosphatase / Q000378:metabolism*; D019298:Glucose-6-Phosphate; D005958:Glucosephosphates / Q000378:metabolism; D007700:Kinetics; D008862:Microsomes, Liver / Q000201:enzymology; D017830:Octoxynol; D011092:Polyethylene Glycols / Q000494:pharmacology; D051381:Rats; D013237:Stereoisomerism; D013379:Substrate Specificity
D005958:Glucosephosphates; D011092:Polyethylene Glycols; D019298:Glucose-6-Phosphate; D017830:Octoxynol; D005941:Glucokinase; D005952:Glucose-6-Phosphatase; D002238:Carbohydrate Epimerases; C019646:aldose 1-epimerase; D005947:Glucose