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B6db references: 22266321

type Journal Article
authors Torrens-Spence MP, Gillaspy G, Zhao B, Harich K, White RH, Li J
title Biochemical evaluation of a parsley tyrosine decarboxylase results in a novel 4-hydroxyphenylacetaldehyde synthase enzyme
journal Biochem Biophys Res Commun
sel selected
ui 22266321
year (2012)
volume 418
number 2
pages 211-6
keywords doi: 10.1016/j.bbrc.2011.12.124
abstract Plant aromatic amino acid decarboxylases (AAADs) are effectively indistinguishable from plant aromatic acetaldehyde syntheses (AASs) through primary sequence comparison. Spectroscopic analyses of several characterized AASs and AAADs were performed to look for absorbance spectral identifiers. Although this limited survey proved inconclusive, the resulting work enabled the reevaluation of several characterized plant AAS and AAAD enzymes. Upon completion, a previously reported parsley AAAD protein was demonstrated to have AAS activity. Substrate specificity tests demonstrate that this novel AAS enzyme has a unique substrate specificity towards tyrosine (km 0.46mM) and dopa (km 1.40mM). Metabolite analysis established the abundance of tyrosine and absence of dopa in parsley extracts. Such analysis indicates that tyrosine is likely to be the sole physiological substrate. The resulting information suggests that this gene is responsible for the in vivo production of 4-hydroxyphenylacetaldehyde (4-HPAA). This is the first reported case of an AAS enzyme utilizing tyrosine as a primary substrate and the first report of a single enzyme capable of producing 4-HPAA from tyrosine.
last changed 2018/05/09 15:57

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