A hexokinase is an enzyme that phosphorylates hexoses (six-carbon sugars), forming hexose phosphate. In most organisms, glucose is the most important substrate of hexokinases, and glucose-6-phosphate the most important product. Hexokinase can transfer an inorganic phosphate group from ATP to a substrate. Hexokinases should not be confused with glucokinase, which is a specific isoform of hexokinase. While other hexokinases are capable of phosphorylating several hexoses, glucokinase acts with a 50-fold lower substrate affinity and its only hexose substrate is glucose.
The enzyme is useful for enzymatic determination of glucose, adenosine-5'-triphosphate (ATP) and creatine phosphokinase when coupled with glucose-6-phosphate dehydrogenase.
White amorphous powder, lyophilized
Enzyme Commission Number
GradeⅢ 150U/mg-solid or more
Phosphoglucose isomerase < 1.0×10⁻¹% 6-Phosphogluconate dehydrogenase < 1.0×10⁻²% Glucose-6-phosphate dehydrogenase < 1.0×10⁻²% Myokinase < 1.0×10⁻²% Glutathione reductase < 5.0×10⁻¹%
approx. 82 kDa (by gel filtration)
pH 4.0-9.0 (25°C, 20hr)
2.3×10⁻⁴M (D-Glucose), 7.7×10⁻⁵M (ATP)
below 45°C (pH 7.0, 30min)
Metal ions, p-chloromercuribenzoate, iodoacetamide, SDS, etc
Hexokinase; EC 22.214.171.124; hexokinase type IV glucokinase; hexokinase D; hexokinase type IV; hexokinase (phosphorylating); ATP-dependent hexokinase; glucose ATP phosphotransferase; ATP: D-hexose 6-phosphotransferase