Human Tryptophan Hydroxylase 1/TPH‑1 Antibody

Tryptophan Hydroxylase 1 (TPH-1) is a 50‑60 kDa intracellular enzyme that belongs to the biopterin-dependent, aromatic amino acid hydroxylase family. It is expressed in gut enterochromaffin cells and pineal gland. TPH-1 catalyzes the hydroxylation of L-Trp, which is the rate-limiting step in serotonin biosynthesis. Human TPH-1 is 444 amino acids (aa) in length. It contains an N-terminal regulatory domain (aa 1‑98), a catalytic region (aa 99‑424), and a C‑terminal Leu-zipper tetramerization domain (aa 425‑444). TPH-1 is phosphorylated on Ser58, and subsequently binds to 14-3-3 proteins, resulting in activation. It functions as a noncovalent Fe-binding 230 kDa homotetramer. There are three potential splice variants. One shows a 29 aa substitution for aa 438‑444, a second shows a 50 aa substitution for aa 157‑444, and a third shows a 68 aa substitution for aa 1‑21. Over aa 102‑403, Human TPH-1 shares 95% aa identical with mouse TPH-1.