Tryptophan

L-isomer of Tryptophan

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 got 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.

Tryptophan Media

Metabolism of l-tryptophan into serotonin and melatonin (left) and niacin (right). Transformed functional groups after each chemical reaction are highlighted in red.
Tryptophan biosynthesis (en)

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.

[1] 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.

[1]