kinase
American Heritage Dictionary:
Top
ki·nase
An enzyme that catalyses the transfer of a phosphate group from ATP to an acceptor (see phosphofructokinase).
Top
any phosphotransferase enzyme that transfers a phosphate group, usually from ATP. Kinases are divided into EC sub-subclasses according to the nature of the phosphate-accepting group: EC 2.7.1 — phosphotransferases with an alcohol group as acceptor; EC 2.7.2 — phosphotransferases with a carboxyl group as acceptor; EC 2.7.3 — phosphotransferases with a nitrogenous group as acceptor; EC 2.7.4 — phosphotransferases with a phosphate group as acceptor. The name is also used for enzymes that transfer a phosphate group from other nucleoside triphosphates. Compare dikinase, pyrophosphokinase, thiokinase.
| kilogram calorie, kilogram, kilodalton | |
| kinasing, kinectin, kinematic viscosity |
Top
1. a subclass of the transferases, comprising the enzymes that catalyze the transfer of a high-energy group from a donor (usually ATP) to an acceptor, and named, according to the acceptor, as creatine kinase, fructokinase, etc.
2. an enzyme that activates a zymogen, and named, according to its source, as enterokinase, streptokinase, etc.
- protein k's — cellular enzymes which utilize ATP to phosphorylate proteins, usually at a selected OH group of serine, threonine or tyrosine residue in the protein, so as to increase or decrease the activity of the protein.
- protein k. C — membrane bound protein kinase designated C because it requires Ca2+ and phosphatidyl serine for its activity. Activated by sn-1,2-diacylglycerol (DAG) produced from phosphatidyl inositol 4,5-bisphosphate. Phosphorylates target proteins such as the insulin receptor, β-adrenergic receptor, glucose transporter, HMG-CoA reductase, cytochrome P-450 and tyrosine hydroxylase.
Wikipedia on Answers.com:
Top
Kinase
See also: Protein kinase
In biochemistry, a kinase[1] is a type of enzyme that transfers phosphate groups from high-energy donor molecules, such as ATP,[2] to specific substrates, a process referred to as phosphorylation. Kinases are part of the larger family of phosphotransferases. Kinases are not to be confused with phosphorylases, which carry out phosphorolysis, the breaking of a bond using an inorganic phosphate group; or with phosphatases, which remove phosphate groups.
Types
One of the largest groups of kinases are protein kinases, which act on and modify the activity of specific proteins. Kinases are used extensively to transmit signals and control complex processes in cells. More than five hundred different kinases have been identified in humans. Their enormous diversity, as well as their role in signaling, makes them an object of study.
Various other kinases act on small molecules such as lipids, carbohydrates, amino acids, and nucleotides, either for signaling or to prime them for metabolic pathways. Kinases are often named after their substrates.
References
See also
- Cyclin-dependent kinase
- Ca2+/calmodulin-dependent protein kinase
- Signal transduction
- G protein-coupled receptor
|
||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
This entry is from Wikipedia, the leading user-contributed encyclopedia. It may not have been reviewed by professional editors (see full disclaimer)
Post a question - any question - to the WikiAnswers community:
Copyrights:
American Heritage Dictionary
The American Heritage® Dictionary of the English Language, Fourth Edition Copyright © 2007, 2000 by Houghton Mifflin Company. Updated in 2009. Published by Houghton Mifflin Company. All rights reserved.
Read more
Oxford Dictionary of Sports Science & Medicine
The Oxford Dictionary of Sports Science & Medicine. Copyright © Michael Kent 1998, 2006, 2007. All rights reserved.
Read more
Oxford Dictionary of Biochemistry
Oxford University Press. Oxford Dictionary of Biochemistry and Molecular Biology © 1997, 2000, 2006 All rights reserved.
Read more
Saunders Veterinary Dictionary
Saunders Comprehensive Veterinary Dictionary 3rd Edition. Copyright © 2007 by D.C. Blood, V.P. Studdert and C.C. Gay, Elsevier. All rights reserved.
Read more
