Dictionary:
cit·rul·line (sĭt'rə-lēn') 
|
[New Latin Citrullus, watermelon genus (from Medieval Latin citrullus, watermelon , from Italian dialectal citrulo , from Late Latin citrium , from Latin citrus, citron) + -INE2.]
| 5min Related Video: citrulline |
| Food and Nutrition: citrulline |
An amino acid formed as a metabolic intermediate, but not involved in proteins, and of no nutritional importance.
| Veterinary Dictionary: citrulline |
An alpha amino acid involved in the urea cycle.
| Wikipedia: Citrulline |
| Citrulline | |
|---|---|
 |
|
| IUPAC name |
2-Amino-5-(carbamoylamino)pentanoic acid
|
| Identifiers | |
| CAS number | 372-75-8 |
| PubChem | 9750 |
| Properties | |
| Molecular formula | C6H13N3O3 |
| Molar mass | 175.19 g mol−1 |
| Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa) | |
| Infobox references | |
The organic compound citrulline is an α-amino acid. Its name is derived from citrullus, the Latin word for watermelon, from which it was first isolated in 1930.[1] It has the idealized formula H2NC(O)NH(CH2)3CH(NH2)CO2H. It is a key intermediate in the urea cycle, the pathway by which mammals excrete ammonia.
Contents |
Citrulline is made from ornithine and carbamoyl phosphate in one of the central reactions in the urea cycle. It is also produced from arginine as a by-product of the reaction catalyzed by NOS family (NOS; EC 1.14.13.39).[2] Arginine is first oxidized into N-hydroxyl-arginine, which is then further oxidized to citrulline concomitant with release of nitric oxide.
Although citrulline is not coded for by DNA directly, several proteins are known to contain citrulline as a result of a posttranslational modification. These citrulline residues are generated by a family of enzymes called peptidylarginine deiminases (PADs), which convert arginine into citrulline in a process called citrullination or deimination. Proteins that normally contain citrulline residues include myelin basic protein (MBP), filaggrin, and several histone proteins, whereas other proteins, such as fibrin and vimentin are susceptible to citrullination during cell death and tissue inflammation.
Patients with rheumatoid arthritis often have detectable antibodies against proteins containing citrulline. Although the origin of this immune response is not known, detection of antibodies reactive with citrulline (anti-citrullinated protein antibodies) containing proteins or peptides is now becoming an important help in the diagnosis of rheumatoid arthritis.[3]
In recent studies, citrulline has been found to relax blood vessels.[4]
Citrulline in the form of citrulline malate is sold as a performance-enhancing athletic dietary supplement which was shown to reduce muscle fatigue in a preliminary clinical trial.[5]
The rind of watermelon (Citrullus lanatus) is a good natural source of citrulline.[6]
This entry is from Wikipedia, the leading user-contributed encyclopedia. It may not have been reviewed by professional editors (see full disclaimer)
| Shopping: citrulline |
 | citrullinuria |
| citrullinemia |
| phosphorylase |
Copyrights:
 |
 | 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 |
 |
| Food and Nutrition. A Dictionary of Food and Nutrition. Copyright © 1995, 2003, 2005 by A. E. Bender and D. A. Bender. All rights reserved. Read more |
 |
| 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 |
 |
| Wikipedia. This article is licensed under the Creative Commons Attribution/Share-Alike License. It uses material from the Wikipedia article "Citrulline". Read more |
Mentioned in
