Glucokinase

Glucokinase (EC 2.7.1.2) is an enzyme that facilitates phosphorylation of glucose to glucose-6-phosphate. Glucokinase occurs in cells in the liver, pancreas, gut, and brain of humans and most other vertebrates. In each of these organs it plays an important role in the regulation of carbohydrate metabolism by acting as a glucose sensor, triggering shifts in metabolism or cell function in response to rising or falling levels of glucose, such as occur after a meal or when fasting. Mutations of the gene for this enzyme can cause unusual forms of diabetes or hypoglycemia.

Glucokinase (GK) is a hexokinase isozyme, related homologously and by evolution to at least three other hexokinases. All of the hexokinases can mediate phosphorylation of glucose to glucose-6-phosphate (G6P), which is the first step of both glycogen synthesis and glycolysis. However, glucokinase is coded by a separate gene and its distinctive kinetic properties allow it to serve a different set of functions. Glucokinase has a lower affinity for glucose than the other hexokinases do, and its activity is localized to a few cell types, leaving the other three hexokinases as more important preparers of glucose for glycolysis and glycogen synthesis for most tissues and organs. Because of this reduced affinity, the activity of glucokinase, under usual physiological conditions, varies substantially according to the concentration of glucose.

Read more about Glucokinase:  Nomenclature, Structure, Genetics, Distribution Among Organ Systems, Distribution Among Species, Function and Regulation, Clinical Significance, As A Drug Target

Other articles related to "glucokinase":

ADP-specific Glucokinase
... In enzymology, an ADP-specific glucokinase (EC 2.7.1.147) also known as ADP-dependent glucokinase is an enzyme that catalyzes the chemical reaction ADP + D-glucose AMP + D-gluco ... In humans, the ADP-dependent glucokinase is encoded by the ADPGK gene ...
Glucokinase - As A Drug Target
... laboratories sponsored by pharmaceutical companies are researching molecules that activate glucokinase in hope that it will be useful in the treatment of ...
Glucokinase Regulatory Protein
... The glucokinase regulatory protein (GKRP) also known as glucokinase (hexokinase 4) regulator (GCKR) is a protein produced in hepatocytes (liver cells) ... GKRP binds and moves glucokinase (GK), thereby controlling both activity and intracellular location of this key enzyme of glucose metabolism ...
Types of Mammalian Hexokinase - Hexokinase IV ("glucokinase")
... Mammalian hexokinase IV, also referred to as glucokinase, differs from other hexokinases in kinetics and functions ... The location of the phosphorylation on a subcellular level occurs when glucokinase translocates between the cytoplasm and nucleus of liver cells ... Glucokinase can only phosphorylate glucose if the concentration of this substrate is high enough its Km for glucose is 100 times higher than that of hexokinases I, II, and III ...