Transaminase

Aspartate transaminase from E. coli with Pyridoxal 5' Phosphate cofactor

WikiDoc Resources for Transaminase
Articles
Most recent articles on Transaminase Most cited articles on Transaminase Review articles on Transaminase Articles on Transaminase in N Eng J Med, Lancet, BMJ
Media
Powerpoint slides on Transaminase Images of Transaminase Photos of Transaminase Podcasts & MP3s on Transaminase Videos on Transaminase
Evidence Based Medicine
Cochrane Collaboration on Transaminase Bandolier on Transaminase TRIP on Transaminase
Clinical Trials
Ongoing Trials on Transaminase at Clinical Trials.gov Trial results on Transaminase Clinical Trials on Transaminase at Google
Guidelines / Policies / Govt
US National Guidelines Clearinghouse on Transaminase NICE Guidance on Transaminase NHS PRODIGY Guidance FDA on Transaminase CDC on Transaminase
Books
Books on Transaminase
News
Transaminase in the news Be alerted to news on Transaminase News trends on Transaminase
Commentary
Blogs on Transaminase
Definitions
Definitions of Transaminase
Patient Resources / Community
Patient resources on Transaminase Discussion groups on Transaminase Patient Handouts on Transaminase Directions to Hospitals Treating Transaminase Risk calculators and risk factors for Transaminase
Healthcare Provider Resources
Symptoms of Transaminase Causes & Risk Factors for Transaminase Diagnostic studies for Transaminase Treatment of Transaminase
Continuing Medical Education (CME)
CME Programs on Transaminase
International
Transaminase en Espanol Transaminase en Francais
Business
Transaminase in the Marketplace Patents on Transaminase
Experimental / Informatics
List of terms related to Transaminase

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]

In biochemistry, a transaminase or an aminotransferase is an enzyme that catalyzes a type of reaction between an amino acid and an α-keto acid. Specifically, this reaction (transamination) involves removing the amino group from the amino acid, leaving behind an α-keto acid, and transferring it to the reactant α-keto acid and converting it into an amino acid. The enzymes are important in the production of various amino acids, and measuring the concentrations of various transaminases in the blood is important in the diagnosing and tracking many diseases. Transaminases require the coenzyme pyridoxal-phosphate, which is converted into pyridoxamine in the first phase of the reaction, when an amino acid is converted into a keto acid. Enzyme-bound pyridoxamine in turn reacts with pyruvate, oxaloacetate, or alpha-ketoglutarate, giving alanine, aspartic acid, or glutamic acid, respectively.

The presence of elevated transaminases can be an indicator of liver damage.

Transaminases in amino acid metabolism in animals

Animals must metabolize proteins to amino acids, at the expense of muscle tissue, when blood sugar is low. The preference of liver transaminases for oxaloacetate or alpha-ketoglutarate plays a key role in funneling nitrogen from amino acid metabolism to Asp and Glu for conversion to urea for excretion of nitrogen. Similarly, in muscles the use of pyruvate for transamination gives Ala, which is carried by the bloodstream to the liver. Here other transaminases regenerate pyruvate, which provides a valuable precursor for gluconeogenesis. This alanine cycle is analogous to the Cori cycle which allows anaerobic metabolism by muscles.

References

• Ghany, Marc & Hoofnagle, Jay H. (2005). Approach to the Patient With Liver Disease. In Dennis L. Kasper, Anthony S. Fauci, Dan L. Longo, Eugene Braunwald, Stephen L. Hauser, & J. Larry Jameson (Eds.), Harrison's Principles of Internal Medicine (16th Edition), pp. 1814–1815. New York: McGraw-Hill.
• Nelson, David L. & Cox, Michael M. (2000). Lehninger Principles of Biochemistry (3rd ed.), pp. 628–631, 634, 828–830. New York: Worth Publishers.

See also

• Valproic acid - a GABA transaminase inhibitor

External links

• MeSH Transaminases

de:Transaminaseit:Transaminasi