Tryptophan (Trp or W) is encoded by the codon UGG. It is an α-amino acid used in the biosynthesis of proteins.
Tryptophan has an α-amino group (which is in the –NH3+ form under biological conditions), and an α-carboxylic acid group (which is in the deprotonated –COO− form under biological conditions). It also has a side chain indole, which makes it a non-polar aromatic amino acid. Tryptophan is essential to humans: the body cannot synthesize it, so it must be obtained from the diet.
Tryptophan is also a precursor to the neurotransmitters serotonin and melatonin.[1]
People get tryptophan by eating protein-rich foods like meat, eggs, and dairy products.
References
- ↑ Slominski, Andrzej; Semak, Igor; Pisarchik, Alexander; Sweatman, Trevor; Szczesniewski, Andre; Wortsman, Jacobo (2002). "Conversion of L-tryptophan to serotonin and melatonin in human melanoma cells". FEBS Letters. 511 (1–3): 102–6. doi:10.1016/s0014-5793(01)03319-1. PMID 11821057. S2CID 7820568.
Encoded (proteinogenic) amino acids |
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| General topics | |
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| By properties | | Aliphatic |
- Alanine
- Branched-chain amino acids (Valine
- Isoleucine
- Leucine)
- Methionine
- Proline
- Glycine
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| Aromatic | |
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| Polar, uncharged | |
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| Positive charge (pKa) |
- Histidine (≈6.1)
- Lysine (≈10.8)
- Arginine (≈12.5)
- Pyrrolysine
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| Negative charge (pKa) | |
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- Amino acids types: Encoded (proteins)
- Essential
- Non-proteinogenic
- Ketogenic
- Glucogenic
- Secondary amino
- Imino acids
- D-amino acids
- Dehydroamino acids
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| K→acetyl-CoA | | lysine→ |
- Saccharopine
- Allysine
- α-Aminoadipic acid
- 2-Oxoadipic acid
- Glutaryl-CoA
- Glutaconyl-CoA
- Crotonyl-CoA
- β-Hydroxybutyryl-CoA
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| leucine→ |
- β-Hydroxy β-methylbutyric acid
- β-Hydroxy β-methylbutyryl-CoA
- Isovaleryl-CoA
- α-Ketoisocaproic acid
- β-Ketoisocaproic acid
- β-Ketoisocaproyl-CoA
- β-Leucine
- β-Methylcrotonyl-CoA
- β-Methylglutaconyl-CoA
- β-Hydroxy β-methylglutaryl-CoA
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| tryptophan→alanine→ |
- N′-Formylkynurenine
- Kynurenine
- Anthranilic acid
- 3-Hydroxykynurenine
- 3-Hydroxyanthranilic acid
- 2-Amino-3-carboxymuconic semialdehyde
- 2-Aminomuconic semialdehyde
- 2-Aminomuconic acid
- Glutaryl-CoA
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| G | G→pyruvate→ citrate | glycine→ serine→ |
- glycine→creatine: Glycocyamine
- Phosphocreatine
- Creatinine
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G→glutamate→ α-ketoglutarate | | histidine→ |
- Urocanic acid
- Imidazol-4-one-5-propionic acid
- Formiminoglutamic acid
- Glutamate-1-semialdehyde
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| proline→ |
- 1-Pyrroline-5-carboxylic acid
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| arginine→ |
- Agmatine
- Ornithine
- Citrulline
- Cadaverine
- Putrescine
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| other | |
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G→propionyl-CoA→ succinyl-CoA | | valine→ |
- α-Ketoisovaleric acid
- Isobutyryl-CoA
- Methacrylyl-CoA
- 3-Hydroxyisobutyryl-CoA
- 3-Hydroxyisobutyric acid
- 2-Methyl-3-oxopropanoic acid
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| isoleucine→ |
- 2,3-Dihydroxy-3-methylpentanoic acid
- 2-Methylbutyryl-CoA
- Tiglyl-CoA
- 2-Methylacetoacetyl-CoA
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| methionine→ |
- generation of homocysteine: S-Adenosyl methionine
- S-Adenosyl-L-homocysteine
- Homocysteine
- conversion to cysteine: Cystathionine
- α-Ketobutyric acid + Cysteine
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| threonine→ | |
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| propionyl-CoA→ | |
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| G→fumarate | |
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| G→oxaloacetate | |
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| Other | |
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Aryl hydrocarbon receptor modulators |
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| AhR |
- Agonists: Dietary carotenoids
- Halogenated aromatic hydrocarbons (e.g., polychlorinated dibenzodioxins (e.g., TCDD), dibenzofurans, biphenyls)
- Tetrapyroles (e.g., bilirubin)
- Tryptophan derivatives (e.g., indigo dye, indirubin)
- Arachidonic acid metabolites (e.g., lipoxin A4, prostaglandin G2)
- Flutamide
- ΙΤΕ
- Modified low-density lipoproteins
- Polycyclic aromatic hydrocarbons (e.g., 3-methylcholanthrene, benzo[a]pyrene, benzanthracenes, benzoflavones (e.g., β-naphthoflavone))
- Tapinarof (benvitimod)
- Antagonists: 7-Ketocholesterol
- CH-223191
- Cyproterone acetate
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- Related page,
- Receptor/signaling modulators
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