Kinase

Kinases are enzymes that other substrates, where in particular hydroxyl groups (-OH), transfer a phosphate residue from a nucleoside triphosphate (for example ATP), and vice versa. They may be prepared by other molecules (such as enzymes ) are activated. They include not only the aminotransferases and glycosyltransferases to the class of transferases. After the EC number classification system they belong in the group EC 2.7.

In the history of biochemistry, the term was " kinase " more broadly. Thus, enzymes were referred to as kinases that convert the zymogens into enzymes. An example is the classic enterokinase, which is now called enteropeptidase.

Kinases in glucose metabolism

A group of kinases phosphorylated hydroxy groups of sugar molecules. These can be found inter alia in the two phases of glycolysis

• In the " collecting phase " (phosphorylation of glucose and conversion to glyceraldehyde -3-phosphate with ATP consumption ): hexokinase or glucokinase and phosphofructokinase
• In the " winning streak " (conversion of glyceraldehyde -3 -phosphate to pyruvate with ATP formation ): phosphoglycerate kinase and pyruvate kinase, two enzymes that are involved in the formation of ATP from phosphorylated metabolites (1,3- bisphosphoglycerate and phosphoenolpyruvate ). In terms of a " reverse reaction " occurs while transferring a phosphate group from a high group transfer potential metabolites on ADP.

Protein kinases

Main article: Protein kinase

More acceptor for kinases are the alcoholic amino acid residues of proteins. The modifying enzymes, protein kinases, are the second most abundant protein in higher cell class. They are either on the type of the modified group ( serine, threonine, tyrosine), divided, or after their activation mechanism (such as protein kinase A, protein kinase B (see insulin / cellular effects ), protein kinase C, protein kinase G). The effect of these kinases can be reversed by specialized protein phosphatases.