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Aromatic L-amino acid decarboxylase is active as a homodimer. Before addition of the pyridoxal phosphate cofactor, the apoenzyme exists in an open conformation. Upon cofactor binding, a large structural transformation occurs as the subunits pull closer and close the active site. This conformational change results in the active, closed ...
An aromatic L-amino acid decarboxylase inhibitor (synonyms: DOPA decarboxylase inhibitor, extracerebral decarboxylase inhibitor, DDCI and AAADI) is a medication of type enzyme inhibitor which inhibits the synthesis of dopamine by the enzyme aromatic L-amino acid decarboxylase (AADC, AAAD, or DOPA decarboxylase).
Tyrosine hydroxylase or tyrosine 3-monooxygenase is the enzyme responsible for catalyzing the conversion of the amino acid L-tyrosine to L-3,4-dihydroxyphenylalanine (L-DOPA). [5] [6] It does so using molecular oxygen (O 2), as well as iron (Fe 2+) and tetrahydrobiopterin as cofactors.
L-Tyrosine is converted into L-DOPA by the enzyme tyrosine hydroxylase, with tetrahydrobiopterin, O 2, and iron (Fe 2+) as cofactors. [25] L-DOPA is converted into dopamine by the enzyme aromatic L-amino acid decarboxylase (also known as DOPA decarboxylase), with pyridoxal phosphate as the cofactor. [25]
In molecular biology, group II pyridoxal-dependent decarboxylases are a family of enzymes including aromatic-L-amino-acid decarboxylase (L-dopa decarboxylase or tryptophan decarboxylase) EC 4.1.1.28 that catalyse the decarboxylation of tryptophan to tryptamine, tyrosine decarboxylase EC 4.1.1.25 that converts tyrosine into tyramine and histidine decarboxylase EC 4.1.1.22 that catalyses the ...
The enzyme dopamine hydroxylase requires copper as a cofactor (not shown in the diagram) and DOPA decarboxylase requires PLP (not shown in the diagram). The rate limiting step in catecholamine biosynthesis through the predominant metabolic pathway is the hydroxylation of L-tyrosine to L-DOPA. [citation needed]
l-DOPA, also known as l-3,4-dihydroxyphenylalanine and used medically as levodopa, is made and used as part of the normal biology of some plants [2] and animals, including humans. Humans, as well as a portion of the other animals that utilize l -DOPA, make it via biosynthesis from the amino acid l -tyrosine .
Metabolism of levodopa by catechol-O-methyltransferase (COMT) and aromatic L-amino acid decarboxylase (AADC). COMT inhibitors prevent the conversion of levodopa to 3- O -methyldopa. A catechol- O -methyltransferase inhibitor ( COMT inhibitor ) is a drug that inhibits the enzyme catechol- O -methyltransferase .