What is a kinase or protein kinase?
According to Stedman’s Medical Dictionary (26th Edition, Williams & Wilkins 1995):
A kinase (ki·nase; ˈkīˌnās,ˈkinās) is
- An enzyme that catalyzes the conversation of a proenzyme to an active enzyme. Examples are a enteropeptidase or enterokinase.
- An enzyme that catalyzes the transfer of phosphate groups to form triphosphates, for example adenonsine-triphosphate or ATP.
However, as defined by Merrian-Webster:
A kinase is
- Any of various enzymes that catalyze the transfer of phosphate groups from a high-energy phosphate-containing molecule such as ATP to a substrate.
The term kinase originated from the term kinetic, known since 1947.
- A protein kinase is any enzyme of a class of enzymes that catalyze the transfer of a phosphate group from ATP to one or more amino acids in the side chain of a protein resulting in a conformational change affecting protein function.
- Kinases are part of the larger family of phosphotransferases, not to be confused with phosphorylases or with phosphatases. Kinases are critical in metabolism, cell division, cell signalling, protein regulation, cellular transport, secretory processes, and many, many other cellular pathways.
- In biochemistry the transfer of phosphate groups from high-energy donor molecules, such as ATP, to specific substrates, is a process referred to as phosphorylation. The phosphorylation of proteins is known to play an important role in various cellular processes such as cell division, metabolism, survival and apoptosis.
- The state of phosphorylation state of a molecule, such as a protein, lipid, or carbohydrate, can affect its activity, reactivity, and its ability to bind to or interact with other molecules.