The principal substrate of physiologic importance of glucokinase is glucose, and the most important product is glucose-6-phosphate (G6P).
The other necessary substrate, from which the phosphate is derived, is adenosine triphosphate (ATP), which is converted to adenosine diphosphate (ADP) when the phosphate is removed.
The reaction catalyzed by glucokinase is:
ATP participates in the reaction in a form complexed to magnesium (Mg) as a cofactor.
Furthermore, under certain conditions, glucokinase, like other hexokinases, can induce phosphorylation of other hexoses (6 carbon sugars) and similar molecules.
Therefore, the general glucokinase reaction is more accurately described as:
Hexose + MgATP²⁻
 → hexose-PO²⁻
₃ + MgADP⁻
 + H⁺
Among the hexose substrates are mannose, fructose, and glucosamine, but the affinity of glucokinase for these requires concentrations not found in cells for significant activity.
The principal substrate of physiologic importance of glucokinase is glucose, and the most important product is glucose-6-phosphate (G6P). The other necessary substrate, from which the phosphate is derived, is adenosine triphosphate (ATP), which is converted to adenosine diphosphate (ADP) when the phosphate is removed. The reaction catalyzed by glucokinase is:
ATP participates in the reaction in a form complexed to magnesium (Mg) as a cofactor. Furthermore, under certain conditions, glucokinase, like other hexokinases, can induce phosphorylation of other hexoses (6 carbon sugars) and similar molecules. Therefore, the general glucokinase reaction is more accurately described as:
Hexose + MgATP²⁻
 → hexose-PO²⁻
₃ + MgADP⁻
 + H⁺
Among the hexose substrates are mannose, fructose, and glucosamine, but the affinity of glucokinase for these requires concentrations not found in cells for significant activity.
Glucokinase