Glucokinase

Glucokinase activators act on hexokinase IV, the glucose sensor of pancreatic beta cells and the liver. Glucokinase (GK) phosphorylates glucose to glucose-6-phosphate with low affinity and without inhibition by its product. Its activity therefore rises and falls with blood glucose over the physiological range. A 1995 study of knockout mice showed that beta-cell glucokinase is required to maintain glucose homeostasis. In 2003 Ro 28-1675 was described as an allosteric activator that binds outside the active site and increases glucose affinity. Later activators in the catalogue include piragliatin, MK-0941 and globalagliatin. PF-04991532 is a hepatoselective activator used to separate liver effects from those in islets.