Branched-chain amino acids
- Branched-chain amino acids
The phrase branched-chain amino acids or BCAA is sometimes used to refer to the amino acids having aliphatic side-chains that are non-linear.These are leucine, isoleucine and valine. The combination of these three essential amino acids make up approximately 1/3 of skeletal muscle in the human body, and play an important role in protein synthesis. BCAA’s are currently used clinically to aid in the recovery of burn victims, as well as for supplementation for strength athletes.
Metabolic Pathway
Description of Pathway
The BCAAs affect this metabolic pathway in three different manners. The first manner through which the metabolic pathway is affected is the increased production of insulin. It has been demonstrated that BCAA supplementation in accordance with carbohydrate intake following resistance exercise increases insulin output by 221%, which is much greater than the 66% supplementation without leucine. Leucine is the most readily oxidized BCAA and therefore the most effective at causing insulin secretion from the pancreas, and stimulating the metabolic pathway. This is important because insulin is the initiating factor that begins the signalling cascade. The second effect is outlined with the red arrows clearly indicating a phosphorylation cascade beginning with the activation of the Ras Rhed and ending with rpS6. The importance of rpS6 is that it induces mRNA translation. This translation leads to the production of proteins to build muscle. The other side of the pathway indicated by the blue arrow induces the action of eIF4G. This initiation factor causes the binding of mRNA within the ribosome thus providing the initial products needed for translation. This leads down to the final product via protein binding and phosphorylation, resulting in eIF4E which induces mRNA translation which in turn leads to chain elongation, and termination, resulting in net protein growth. Fact|date=September 2008
References
*
*
*
ee also
* Branched-chain alpha-keto acid dehydrogenase complex
* Branched chain aminotransferase
External links
*
Wikimedia Foundation.
2010.
Look at other dictionaries:
branched-chain-amino-acid transaminase — branched chain ami·no ac·id trans·am·i·nase (brancht chān ə meґno asґid trans amґĭ nās) [EC 2.6.1.42] an enzyme of the transferase class that catalyzes the removal of the α amino group of leucine, isoleucine, or valine to … Medical dictionary
branched-chain amino acids — leucine, isoleucine, and valine; they are incorporated into proteins or catabolized for energy … Medical dictionary
branched-chain α-keto acid dehydrogenase — branched chain α ke·to ac·id de·hy·dro·gen·ase (brancht chān keґto asґid de hiґdro jən ās) an enzyme of the oxidoreductase class that is a component of the multienzyme branched chain α keto acid dehydrogenase complex (q.v … Medical dictionary
Branched chain aminotransferase — protein Name=branched chain aminotransferase 1, cytosolic caption= width= HGNCid=976 Symbol=BCAT1 AltSymbols=BCT1 EntrezGene=586 OMIM=113520 RefSeq=NM 005504 UniProt=P54687 PDB= ECnumber=2.6.1.42 Chromosome=12 Arm=p Band=ter… … Wikipedia
Branched-chain alpha-keto acid dehydrogenase complex — protein Name=2 oxoisovalerate dehydrogenase (lipoamide) caption= width= HGNCid=8523 Symbol=OVD1A AltSymbols= EntrezGene=5014 OMIM= RefSeq= UniProt= PDB= ECnumber=1.2.4.4 Chromosome= Arm= Band= LocusSupplementaryData=The branched chain α keto acid … Wikipedia
branched-chain α-keto acid dehydrogenase complex — a multienzyme complex composed of 3 methyl 2 oxobutanoate dehydrogenase (2 methylpropanoyl transferring) [EC 1.2.4.4] (more commonly called branched chain α keto acid dehydrogenase), dihydrolipoyllysine residue (2 methylpropanoyl)transferase … Medical dictionary
branched-chain keto acid — any of the keto acids formed by oxidative decarboxylation of branched chain amino acids … Medical dictionary
Amino acid — This article is about the class of chemicals. For the structures and properties of the standard proteinogenic amino acids, see Proteinogenic amino acid. The generic structure of an alpha amino acid in its unionized form … Wikipedia
Proteinogenic amino acid — Proteinogenic amino acids are those amino acids that can be found in proteins and require cellular machinery coded for in the genetic code [1] of any organism for their isolated production. There are 22 standard amino acids, but only 21 are found … Wikipedia
Essential amino acid — An essential amino acid or indispensable amino acid is an amino acid that cannot be synthesized de novo by the organism (usually referring to humans), and therefore must be supplied in the diet. Contents 1 Essentiality vs. conditional… … Wikipedia
