Search results
Results from the WOW.Com Content Network
4-Hydroxyphenylpyruvate dioxygenase (HPPD), also known as α-ketoisocaproate dioxygenase (KIC dioxygenase), is an Fe(II)-containing non-heme oxygenase that catalyzes the second reaction in the catabolism of tyrosine - the conversion of 4-hydroxyphenylpyruvate into homogentisate.
The gene affected is the HPD gene encoding 4-hydroxyphenylpyruvic acid dioxygenase, on chromosome 12q24. [4] It is unusual in that most other inborn errors of metabolism are caused by loss-of-function mutations, and hence have recessive inheritance (condition occurs only if both copies are mutated).
Tyrosinemia type III is a rare disorder caused by a deficiency of the enzyme 4-hydroxyphenylpyruvate dioxygenase (EC 1.13.11.27), encoded by the gene HPD. [2] This enzyme is abundant in the liver, and smaller amounts are found in the kidneys. It is one of a series of enzymes needed to break down tyrosine.
4-Hydroxyphenylpyruvate dioxygenase (HPPD) is an enzyme found in both plants and animals, which catalyzes the catabolism of the amino acid tyrosine. [4] Preventing the breakdown of tyrosine has three negative consequences: the excess of tyrosine stunts growth; the plant suffers oxidative damage due to lack of tocopherols (vitamin E); and ...
4-Hydroxyphenylpyruvic acid (4-HPPA) is an intermediate in the metabolism of the amino acid phenylalanine. The aromatic side chain of phenylalanine is hydroxylated by the enzyme phenylalanine hydroxylase to form tyrosine. The conversion from tyrosine to 4-HPPA is in turn catalyzed by tyrosine aminotransferase. [2]
Alkaptonuria is a genetic disease that results in a deficiency of homogentisate 1,2-dioxygenase, which is responsible for catalyzing the formation of 4-maleylacetoacetate from homogentisate. [21] Buildup of homogentisic acid can result in heart valve damage, kidney stones and damage to cartilage in the body. [22]
The compound exists in equilibrium with its (E)- and (Z)-enol tautomers.[citation needed] It is a product from the oxidative deamination of phenylalanine.When the activity of the enzyme phenylalanine hydroxylase is reduced, the amino acid phenylalanine accumulates and gets converted into phenylpyruvic acid (phenylpyruvate), which leads to 'Phenylketonuria (PKU)' instead of 'tyrosine' which is ...
The clinical presentation of congenital PDH deficiency is typically characterized by heterogenous neurological features that usually appear within the first year of life. In addition, patients usually show severe hyperventillation due to profound metabolic acidosis mostly related to lactic acidosis.