Search results
Results from the WOW.Com Content Network
The enzyme phenylalanine ammonia lyase (EC 4.3.1.24) catalyzes the conversion of L-phenylalanine to ammonia and trans-cinnamic acid.: [1] L -phenylalanine = trans -cinnamate + NH 3 Phenylalanine ammonia lyase (PAL) is the first and committed step in the phenyl propanoid pathway and is therefore involved in the biosynthesis of the polyphenol ...
In plants, all phenylpropanoids are derived from the amino acids phenylalanine and tyrosine. Phenylalanine ammonia-lyase (PAL, a.k.a. phenylalanine/tyrosine ammonia-lyase) is an enzyme that transforms L-phenylalanine and tyrosine into trans-cinnamic acid and p-coumaric acid, respectively.
The pathway starts with two substrates, phosphoenol pyruvate and erythrose-4-phosphate, and ends with chorismate (chrorismic acid), a substrate for the three aromatic amino acids. The fifth enzyme involved is the shikimate kinase , an enzyme that catalyzes the ATP -dependent phosphorylation of shikimate to form shikimate 3-phosphate (shown in ...
These enzymes primarily hydroxylate the amino acids L-phenylalanine, L-tyrosine, and L-tryptophan, respectively. The AAAH enzymes are functionally and structurally related proteins which act as rate-limiting catalysts for important metabolic pathways. [1]
In plants, the shikimate pathway first leads to the formation of chorismate, which is the precursor of phenylalanine, tyrosine, and tryptophan. These aromatic amino acids are the precursors of many secondary metabolites , all essential to a plant's biological functions, such as the hormones salicylate and auxin .
Fumarylacetoacetate hydrolase (FAH) is a protein homodimer which cleaves fumarylacetoacetate at its carbon-carbon bond during a hydrolysis reaction. [8] As a critical enzyme in phenylalanine and tyrosine metabolism, 4-Fumarylacetoacetate hydrolase catalyzes the final step in the catabolism of 4-fumarylacetoacetate and water into acetoacetate, fumarate, and H + respectively. [9]
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]
3-Deoxy-D-arabinoheptulosonate 7-phosphate (DAHP) synthase (EC 2.5.1.54) is the first enzyme in a series of metabolic reactions known as the shikimate pathway, which is responsible for the biosynthesis of the amino acids phenylalanine, tyrosine, and tryptophan. Since it is the first enzyme in the shikimate pathway, it controls the amount of ...