Alkaptonuria (AKU) is a rare autosomal recessive disorder that results from a deficiency of the homogentisic acid dioxygenase
(HGD) activity, which is the third enzyme in tyrosine degradation.
Aberrant oxidation of lipofuscin to neuromelanin and insufficient cysteine dioxygenase
leading to abnormal iron accumulation in the brain is the proposed hypothesis.
Also, further cleavage of catechol by catechol 1,2 dioxygenase
or catechol 2,3 dioxygenase
was detected by formation of cis,cis-muconic acid at 260nm or muconic acid semialdehyde at 375 nm respectively.
HMB is a physiological metabolite synthesized in a minor pathway of leucine metabolism by the cytosolic enzyme 2-ketoisocaproate dioxygenase
. Like L-leucine itself, HMB has been shown to stimulate protein synthesis via the mTOR signal transduction pathway (2).
Point action of NTBC is the second step of tyrosine catabolic pathway by inhibiting 4-hydroxyphenylpyruvate dioxygenase
(14) (Figure 1).
The TET2 gene encodes a methylcytosine dioxygenase
that catalyzes the conversion of methylcytosine to 5-hydroxymethylcytosine.
The first reaction in carnitine biosynthesis involves the hydroxylation of trimethyllysine to 3-hydroxy-trimethyllysine by trimethyllysine dioxygenase
According to a new study published in the Nature Journal Scientific Reports, high levels of this enzyme, indoleamine 2,3 dioxygenase
(IDO) at diagnosis also identifies those who might benefit most by taking an IDO inhibitor along with their standard therapy.
Indoleamine 2,3 dioxygenase
and metabolic control of immune responses.
The TET enzyme contains a catalytic C-terminal Cys-rich (CD domain) and double-stranded beta helix region domains that show dioxygenase
In fact, nitisinone 2-(2-nitro-4-trifluoro-methylbenzyol)-1,3 cyclohexanedione, NTBC) is a potent inhibitor of 4-hydroxyphenylpyruvate dioxygenase
, an enzyme that is upstream of fumarylacetoacetase, and most patients present a rapid decrease in the concentrations of succinylacetone (2) when under NTBC.