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Maleylacetoacetate
4-Maleylacetoacetate (4-maleylacetoacetatic acid) is an intermediate in the metabolism of tyrosine. It is converted to fumarylacetoacetate by the enzyme 4-maleylacetoacetate cis-trans-isomerase. Gluthathione coenzymatically helps in conversion to fumarylacetoacetic acid. See also * Homogentisate 1,2-dioxygenase Homogentisate 1,2-dioxygenase (homogentisic acid oxidase, homogentisate oxidase, homogentisicase) is an enzyme which catalyzes the conversion of homogentisate to 4-maleylacetoacetate. Homogentisate 1,2-dioxygenase or HGD is involved in the ca ... Beta-keto acids Enones Diketones {{biochem-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
4-maleylacetoacetate Cis-trans-isomerase
In enzymology, maleylacetoacetate isomerase () is an enzyme that catalysis, catalyzes the chemical reaction :4-maleylacetoacetate \rightleftharpoons 4-fumarylacetoacetate This enzyme belongs to the family of isomerases, specifically Cis-trans isomerism, ''cis''-''trans'' isomerases. The List of enzymes, systematic name of this enzyme class is 4-maleylacetoacetate ''cis''-''trans''-isomerase. 4-Maleylacetoacetate isomerase is an enzyme involved in the degradation of Phenylalanine, L-phenylalanine. It is encoded by the gene glutathione S-transferase zeta 1, or GSTZ1. This enzyme catalyzes the conversion of 4-Maleylacetoacetic acid, 4-maleylacetoacetate to Fumarylacetoacetic acid, 4-fumarylacetoacetate. 4-Maleylacetoacetate isomerase belongs to the zeta class of the glutathione S-transferase (GST) superfamily.; Mechanism In the phenylalanine degradation pathway, 4-maleylacetoacetate isomerase catalyzes a ''cis''-''trans'' isomerization of 4-maleylacetoacetate to fumarylace ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tyrosine
-Tyrosine or tyrosine (symbol Tyr or Y) or 4-hydroxyphenylalanine is one of the 20 standard amino acids that are used by cells to synthesize proteins. It is a conditionally essential amino acid with a polar side group. The word "tyrosine" is from the Greek ''tyrós'', meaning ''cheese'', as it was first discovered in 1846 by German chemist Justus von Liebig in the protein casein from cheese. It is called tyrosyl when referred to as a functional group or side chain. While tyrosine is generally classified as a hydrophobic amino acid, it is more hydrophilic than phenylalanine. It is encoded by the codons UAC and UAU in messenger RNA. The one-letter symbol Y was assigned to tyrosine for being alphabetically nearest of those letters available. Note that T was assigned to the structurally simpler threonine, U was avoided for its similarity with V for valine, W was assigned to tryptophan, while X was reserved for undetermined or atypical amino acids. The mnemonic t''Y''rosine was ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Homogentisate 1,2-dioxygenase
Homogentisate 1,2-dioxygenase (homogentisic acid oxidase, homogentisate oxidase, homogentisicase) is an enzyme which catalyzes the conversion of homogentisate to 4-maleylacetoacetate. Homogentisate 1,2-dioxygenase or HGD is involved in the catabolism of aromatic rings, more specifically in the breakdown of the amino acids tyrosine and phenylalanine. HGD appears in the metabolic pathway of tyrosine and phenylalanine degradation once the molecule homogentisate is produced. Homogentisate reacts with HGD to produce maleylacetoacetate, which then is further used in the metabolic pathway. HGD requires the use of Fe2+ and O2 in order to cleave the aromatic ring of homogentisate. Image:Homogentisic acid.svg, homogentisate Image:4-maleylacetoacetic acid.svg, 4-maleylacetoacetate Enzyme active site The active site of Homogentisate 1,2-dioxygenase was determined through the crystal structure, which was captured through the work of Titus et al. Through the crystal structure the active ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fumarylacetoacetate
Fumarylacetoacetic acid (fumarylacetoacetate) is an intermediate in the metabolism of tyrosine. It is formed through the conversion of maleylacetoacetate into fumarylacetoacetate by the enzyme maleylacetoacetate isomerase. See also * Fumarylacetoacetate hydrolase Fumarylacetoacetase is an enzyme that in humans is encoded by the ''FAH'' gene located on chromosome 15. The enzyme is involved in the catabolism of the amino acid tyrosine in humans. Function Fumarylacetoacetate hydrolase (FAH) is a protein hom ... References Dicarboxylic acids Beta-keto acids Enones {{biochem-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Enzyme
An enzyme () is a protein that acts as a biological catalyst by accelerating chemical reactions. The molecules upon which enzymes may act are called substrate (chemistry), substrates, and the enzyme converts the substrates into different molecules known as product (chemistry), products. Almost all metabolism, metabolic processes in the cell (biology), cell need enzyme catalysis in order to occur at rates fast enough to sustain life. Metabolic pathways depend upon enzymes to catalyze individual steps. The study of enzymes is called ''enzymology'' and the field of pseudoenzyme, pseudoenzyme analysis recognizes that during evolution, some enzymes have lost the ability to carry out biological catalysis, which is often reflected in their amino acid sequences and unusual 'pseudocatalytic' properties. Enzymes are known to catalyze more than 5,000 biochemical reaction types. Other biocatalysts include Ribozyme, catalytic RNA molecules, also called ribozymes. They are sometimes descr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gluthathione
Glutathione (GSH, ) is an organic compound with the chemical formula . It is an antioxidant in plants, animals, fungi, and some bacteria and archaea. Glutathione is capable of preventing damage to important cellular components caused by sources such as reactive oxygen species, free radicals, peroxides, lipid peroxides, and heavy metals. It is a tripeptide with a gamma peptide linkage between the carboxyl group of the glutamate side chain and cysteine. The carboxyl group of the cysteine residue is attached by normal peptide linkage to glycine. Biosynthesis and occurrence Glutathione biosynthesis involves two adenosine triphosphate-dependent steps: *First, γ-glutamylcysteine is synthesized from L-glutamate and L-cysteine. This conversion requires the enzyme glutamate–cysteine ligase (GCL, glutamate cysteine synthase). This reaction is the rate-limiting step in glutathione synthesis. *Second, glycine is added to the C-terminal of γ-glutamylcysteine. This condensation is cata ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
