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.
Hexokinase, Native (Saccharomyces cerevisiae)
Type I, Lyophilized powder containing phosphate/Citrate pH approx. 7.0; Type II, Type III, Lyophilized powder containing approx. 15% sodium Citrate.
Enzyme Commission Number
Type I, > 350 units/mg protein; Type II, > 25 units/mg protein (biuret); Type III, > 130 units/mg protein (biuret).
~ 54 kDa (monomer); ~110 kDa (dimer)
One unit will phosphorylate 1.0 μmole of D-glucose per min at pH 7.6 at 25°C, unless otherwise indicated below.
Hexokinase requires Mg2+ ions (KM = 2.6 mM) for activity. Hexokinase is activated by catecholamines and related compounds.
sorbose-1-phosphate, polyphosphates, 6-deoxy-6-fluoroglucose, 2-C-hydroxy-methylglucose, xylose, lyxose, and thiol reactive compounds (Hg2+ and 4-chloromercuribenzoate)
Predominantly the PII isoform, produced from an overexpressing yeast strain.
ATP binding; catalytic activity; hexokinase activity; ATP binding; catalytic activity; hexokinase activity
hexokinase type IV glucokinase; hexokinase D; hexokinase type IV; hexokinase (phosphorylating); ATP-dependent hexokinase; glucose ATP phosphotransferase; hexokinase; ATP:D-hexose 6-phosphotransferase; EC 22.214.171.124; 9001-51-8