| phenylalanine ammonia-lyase | |||||||||
|---|---|---|---|---|---|---|---|---|---|
 PDB rendering based on 1T6J. | |||||||||
| Identifiers | |||||||||
| EC no. | 4.3.1.24 | ||||||||
| CAS no. | 9024-28-6 | ||||||||
| Databases | |||||||||
| IntEnz | IntEnz view | ||||||||
| BRENDA | BRENDA entry | ||||||||
| ExPASy | NiceZyme view | ||||||||
| KEGG | KEGG entry | ||||||||
| MetaCyc | metabolic pathway | ||||||||
| PRIAM | profile | ||||||||
| PDB structures | RCSB PDB PDBe PDBsum | ||||||||
| Gene Ontology | AmiGO / QuickGO | ||||||||
| |||||||||
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 + NH3
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 compounds such as flavonoids, phenylpropanoids, and lignin in plants.[2][3] Phenylalanine ammonia lyase is found widely in plants, as well as some bacteria, yeast, and fungi, with isoenzymes existing within many different species. It has a molecular mass in the range of 270–330 kDa.[1][4] The activity of PAL is induced dramatically in response to various stimuli such as tissue wounding, pathogenic attack, light, low temperatures, and hormones.[1][5] PAL has recently been studied for possible therapeutic benefits in humans afflicted with phenylketonuria.[6] It has also been used in the generation of L-phenylalanine as precursor of the sweetener aspartame.[7]
The enzyme is a member of the ammonia lyase family, which cleaves carbon–nitrogen bonds. Like other lyases, PAL requires only one substrate for the forward reaction, but two for the reverse. It is thought to be mechanistically similar to the related enzyme histidine ammonia-lyase (EC:4.3.1.3, HAL).[8] The systematic name of this enzyme class is L-phenylalanine ammonia-lyase (trans-cinnamate-forming). Previously, it was designated as EC 4.3.1.5, but that class has been redesignated as EC 4.3.1.24 (phenylalanine ammonia-lyases), EC 4.3.1.25 (tyrosine ammonia-lyases), and EC 4.3.1.26 (phenylalanine/tyrosine ammonia-lyases). Other names in common use include tyrase, phenylalanine deaminase, tyrosine ammonia-lyase, L-tyrosine ammonia-lyase, phenylalanine ammonium-lyase, PAL, and L-phenylalanine ammonia-lyase.
- ^ a b c Camm EL, Towers G (1 May 1973). "Phenylalanine ammonia lyase". Phytochemistry. 12 (5): 961–973. Bibcode:1973PChem..12..961C. doi:10.1016/0031-9422(73)85001-0.
- ^ Fritz RR, Hodgins DS, Abell CW (August 1976). "Phenylalanine ammonia-lyase. Induction and purification from yeast and clearance in mammals". The Journal of Biological Chemistry. 251 (15): 4646–50. doi:10.1016/S0021-9258(17)33251-9. PMID 985816.
- ^ Tanaka Y, Matsuoka M, Yamanoto N, Ohashi Y, Kano-Murakami Y, Ozeki Y (August 1989). "Structure and characterization of a cDNA clone for phenylalanine ammonia-lyase from cut-injured roots of sweet potato". Plant Physiology. 90 (4): 1403–7. doi:10.1104/pp.90.4.1403. PMC 1061903. PMID 16666943.
- ^ Appert C, Logemann E, Hahlbrock K, Schmid J, Amrhein N (October 1994). "Structural and catalytic properties of the four phenylalanine ammonia-lyase isoenzymes from parsley (Petroselinum crispum Nym.)". European Journal of Biochemistry. 225 (1): 491–9. doi:10.1111/j.1432-1033.1994.00491.x. PMID 7925471.
- ^ Hahlbrock K, Grisebach H (1 June 1979). "Enzymic Controls in the Biosynthesis of Lignin and Flavonoids". Annual Review of Plant Physiology. 30 (1): 105–130. doi:10.1146/annurev.pp.30.060179.000541.
- ^ Cite error: The named reference
PAL therapywas invoked but never defined (see the help page). - ^ Evans C, Hanna K, Conrad D, Peterson W, Misawa M (1 February 1987). "Production of phenylalanine ammonia-lyase (PAL): isolation and evaluation of yeast strains suitable for commercial production of L-phenylalanine". Applied Microbiology and Biotechnology. 25 (5): 406–414. doi:10.1007/BF00253309. S2CID 40066810.
- ^ Schwede TF, Rétey J, Schulz GE (April 1999). "Crystal structure of histidine ammonia-lyase revealing a novel polypeptide modification as the catalytic electrophile". Biochemistry. 38 (17): 5355–61. doi:10.1021/bi982929q. PMID 10220322.