2012), whose roles are probably involved with the formation of chitin-binding dihydroxyphenylalanine
residues and carbonate mineral formation, respectively.
It is due to deficiency of enzyme tyrosinase which is responsible for the hydroxylation of L-tyrosine to 3, 4, dihydroxyphenylalanine
(DOPA) and its subsequent oxidation to dopaquinone.
The tyrosinase, encoded by tyrosinase (TYR) gene, is known to be the rate-limiting enzyme affecting the production of melanin pigment (Sanchez-Ferrer et al., 1995), which oxidates tyrosine to dihydroxyphenylalanine
(DOPA) (Lerner and Fitzpatrick, 1950) and determines which type of melanin (eumelanin or phaeomelanin) could be synthesized (Ito et al., 2000).
Derivation of urinary dopamine from plasma dihydroxyphenylalanine
Key to its adhesiveness is a family of unique proteins called mussel adhesive proteins, which contain a high concentration of the catecholic amino acid DOPA (dihydroxyphenylalanine
(39.) Ozawa K, et at Translational incorporation of l-3,4- dihydroxyphenylalanine
Tyrosinase catalyses the formation of dopa (dihydroxyphenylalanine
) from tyrosine.
It is thought to be produced when tyrosine, an amino acid in the skin, is oxidized by the enzyme tyrosinase to form 3,4 dihydroxyphenylalanine
(DOPA), which is further oxidized by UV light and the catalyst tyrosinase to form an indole derivative which polymerizes to melanin.