What kind of enzyme is hydroxylase?
Hydroxylases are enzymes which add an hydroxyl group to organic compounds. This addition is the first step of aerobic oxidative degradation. Secondary structure of Human phenylalanine hydroxylase catalytic domain (PDB entry 1pah).
What cofactor does phenylalanine hydroxylase require?
tetrahydrobiopterin
The natural cofactor of phenylalanine hydroxylase (PAH), tetrahydrobiopterin (BH4), regulates the enzyme activity as well as being essential in catalysis.
What is the cofactor of tyrosine hydroxylase?
Like the other aromatic amino acid hydroxylases (AAAHs), tyrosine hydroxylase use the cofactor tetrahydrobiopterin (BH4) under normal conditions, although other similar molecules may also work as a cofactor for tyrosine hydroxylase.
What enzyme breaks phenylalanine?
Babies with PKU are missing an enzyme called phenylalanine hydroxylase. It is needed to break down the essential amino acid phenylalanine. Phenylalanine is found in foods that contain protein. Without the enzyme, levels of phenylalanine build up in the body.
What is PAH deficiency?
Phenylalanine hydroxylase deficiency (PAH deficiency), also called phenylketonuria (PKU), is an inherited disease in which the body cannot properly process the amino acid phenylalanine due to a deficient enzyme called phenylalanine hydroxylase. PAH deficiency is caused by mutations in the PAH gene.
Is phenylalanine 4 hydroxylase a protein?
PAH (Phenylalanine Hydroxylase) is a Protein Coding gene. Diseases associated with PAH include Phenylketonuria and Hyperphenylalaninemia.
Why is phenylalanine converted to tyrosine?
Phenylalanine is an essential amino acid. To enter the tyrosine pathway, phenylalanine is converted into tyrosine by the enzyme phenylalanine hydroxylase, which has tetrahydrobiopterin as a cofactor. Deficiency of the enzyme or of its cofactor causes accumulation of phenylalanine in the body fluids and tissues.
What foods are rich in tyrosine?
Dietary Sources Tyrosine is found in soy products, chicken, turkey, fish, peanuts, almonds, avocados, bananas, milk, cheese, yogurt, cottage cheese, lima beans, pumpkin seeds, and sesame seeds.
What are the dangers of phenylalanine?
Phenylalanine can cause intellectual disabilities, brain damage, seizures and other problems in people with PKU . Phenylalanine occurs naturally in many protein-rich foods, such as milk, eggs and meat. Phenylalanine is also sold as a dietary supplement.
What happens if you have too much phenylalanine?
A musty odor in the breath, skin or urine, caused by too much phenylalanine in the body. Neurological problems that may include seizures. Skin rashes (eczema) Fair skin and blue eyes, because phenylalanine can’t transform into melanin — the pigment responsible for hair and skin tone.
Why is phenylalanine bad?
What type of protein is phenylalanine hydroxylase?
Phenylalanine hydroxylase (PAH) (EC 1.14. 16.1) is an enzyme that catalyzes the hydroxylation of the aromatic side-chain of phenylalanine to generate tyrosine.
What is the cofactor of phenylalanine hydroxylase?
The hydroxylation of phenylalanine requires free oxygen and a helper molecule (cofactor), tetrahydrobiopterin. Although the exact mechanism of the enzyme action is not known, it is clear that the cofactor interacts with a few conserved residues in the enzyme and the primary function of the iron ion is to stabilize this cofactor.
How is the expression of tyrosine hydroxylase affected?
It has been shown that the expression of tyrosine hydroxylase can be affected by the expression of SRY. The down regulation of the SRY gene in the substantia nigra can result in a decrease in tyrosine hydroxylase expression.
How does phenylalanine hydroxylase act on dihydrobiopterin?
Yet another enzyme acts on dihydrobiopterin to restore the original form of the cofactor, which is then used in another cycle of hydroxylation. Mutations in phenylalanine hydroxylase can block the conversion of phenylalanine to tyrosine. Several hundred mutations have been documented in this enzyme.
What kind of enzyme is dopamine beta hydroxylase?
Dopamine beta-hydroxylase ( DBH ), also known as dopamine beta-monooxygenase, is an enzyme ( EC 1.14.17.1) that in humans is encoded by the DBH gene. Dopamine beta-hydroxylase catalyzes the chemical reaction : The three substrates of this enzyme are Dopamine (3,4-dihydroxyphenethylamine),…