Glucokinase from human liver

The gene encoding glucokinase (GCK) is alternatively spliced to generate three different forms of the enzyme; one found in the pancreas and two found in the liver. The enzyme is expressed as a monomer and possesses one glucose-binding site. The gene encoding GCK is localized on human chromosome 7. Recombinant human liver glucokinase (Accession# NP_277042)) has a C-terminal FLAG tag and has 474 amino acid residues.

Glucose is phosphorylated to glucose-6-phosphate by glucokinases. The main function of glucokinase (GCK) is to regulate carbohydrate metabolism. The enzyme triggers the release of insulin in β-cells of pancreas. It can be useful for studies including enzyme kinetics, activator screening and kinase selectivity. Mutation in the gene encoding this protein is associated with a rare form of diabetes and the protein may also have a role in type 2 diabetes.

50 mM potassium phosphate pH 7.4, 50 mM sodium chloride, 0.5 mM DTT, 0.5 mM EDTA, and 2.5% glycerol.

One unit is defined as the amount of enzyme that will convert 1 pmol of NADP to NADPH at 30°C. Assay conditions: 25 mM HEPES, pH 7.5, 2 mM MgCl2, 1.0 mM DTT, 0.5 mM NADP, 2 mM ATP, 25 mM glucose, 100 μg/ml BSA, 20 units/ml glucose 6-phosphate dehydrogenase, and 10 nM human liver glucokinase at 30°C for 30 min.