Amines that are neurotransmitters and hormones can be derived from amino acids. Dopamine and serotonin are 2 such neurotransmitters. Which amino acids do they come from?
They come from tyrosine and tryptophan, respectively.
Both are formed by enzymatically controlled hydroxylation and decarboxylation reactions.
Dopamine is formed by the metabolism of tyrosine.
The enzyme tyrosine hydroxylase first hydroxylates tyrosine to L-3,4-dihydroxyphenylalanine (L-DOPA).
In a second step, the enzyme L-DOPA decarboxylase decarboxylates L-DOPA to form dopamine.
Serotonin is formed by the metabolism of tryptophan.
In the first step, the enzyme tryptophan hydroxylase hydroxylates tryptophan to form 5-hydroxy tryptophan (5-HTP).
In a second step, the enzyme aromatic L-amino acid decarboxylase decarboxylates 5-HTP to form serotonin.