Phenolic acid decarboxylases

Gury, J., Barthelmebs, L., Tran, N. R, Divies, C., Cavin, J.-F. (2004). Cloning, deletion, and characterization of PadR, the transcriptional repressor of the phenolic acid decarboxylase-encoding padA gene of Lactobacillus plantarum. Appl. Environ. Microbiol., 70, 2146-2153. 

Some phenolic acid decarboxylases [60, 62-65] which catalyze the conversion of hydroxycinnamic acids into styrenes are also of interest. Considering the structural data available to date, both enzymes work with different mechanisms ... 

Phenolic acid decarboxylase (PADC) is a metal-independent acid-base catalyst [67-69]. 

Prim N, Pastor FU, Diaz P (2003) Biochemical studies on cloned Bacillus sp. BP-7 phenolic acid decarboxylase PadA. Appl Microbiol Biotechnol 63 51-56... 

Matte A, Grosse S, Bergeron H, Abokitse K, Lau PCK (2010) Structural analysis of Bacillus pumilus phenolic acid decarboxylase, a lipocalin-fold enzyme. Acta Crystallogr F66 1407-1414... 

Because LCEC had its initial impact in neurochemical analysis, it is not, surprising that many of the early enzyme-linked electrochemical methods are of neurologically important enzymes. Many of the enzymes involved in catecholamine metabolism have been determined by electrochemical means. Phenylalanine hydroxylase activity has been determined by el trochemicaUy monitoring the conversion of tetrahydro-biopterin to dihydrobiopterin Another monooxygenase, tyrosine hydroxylase, has been determined by detecting the DOPA produced by the enzymatic reaction Formation of DOPA has also been monitored electrochemically to determine the activity of L-aromatic amino acid decarboxylase Other enzymes involved in catecholamine metabolism which have been determined electrochemically include dopamine-p-hydroxylase phenylethanolamine-N-methyltransferase and catechol-O-methyltransferase . Electrochemical detection of DOPA has also been used to determine the activity of y-glutamyltranspeptidase The cytochrome P-450 enzyme system has been studied by observing the conversion of benzene to phenol and subsequently to hydroquinone and catechol... 

Bhat, C.S. and Ramasarma, T., Effect of phenyl and phenolic acids on mevalonate-5-phosphate kinase and mevalonate-5-pyrophosphate decarboxylase of the rat brain, J. Neurochem., 32, 1531, 1979. 

Grape compounds which can enter the yeast cell either by diffusion of the undissociated lipophilic molecule or by carrier-mediated transport of the charged molecule across the cell membrane are potentially subject to biochemical transformations by enzymatic functions. A variety of biotransformation reactions of grape compounds that have flavour significance are known. One of the earlier studied biotransformations in yeast relates to the formation of volatile phenols from phenolic acids (Thurston and Tubb 1981). Grapes contain hydroxycinnamic acids, which are non-oxidatively decarboxylated by phenyl acryl decarboxylase to the vinyl phenols (Chatonnet et al. 1993 Clausen et al. 1994). 

Grapes contain several hydroxycinnamic acids, p-coumaric, caffeic, ferulic and sinapic acids, which exist as free acids and esterified with tartaric acid. Saccha-romyces species can take up free acids to produce the corresponding vinyl phenol catalysed by hydroxycinnamate decarboxylase (phenylacrylic acid decarboxylase Padlp) (Fig 8D.11) (Chatonnet et al. 1992b Chatonnet et al. 1993 Edlin et al. 1995). Vinyl phenols are unstable and highly reactive. Dekkera bruxellensis is one of few wine microorganisms that can further reduce vinyl phenols to highly stable ethyl phenols in wine. Vinyl phenols can also react with anthocyanins to form vinyl derivatives, a reaction that is favoured by fermentation yeast having hydroxycinnamate decarboxylase activity (Morata et al. 2006). 

Decarboxylase Decarboxylation of amino acids and simple phenolic acids, primarily p-hydroxylated L-Dopa, tyrosine... 

The partially-purified extract oxidised a range of phenolic substrates, and also contained proteinases and amino acid decarboxylases. Preincubation of a toluene-treated soil enzyme preparation for 12h at 37°C did not affect diphenol oxidase activities, ie. the oxidases appeared to be resistant to attack by the coextracted soil proteinases. Addition of hyaluronidase before preincubation also was without effect. Preincubation with the microbial proteinase, Pronase for I8h at 37°C decreased diphenol oxidase activities by 307o, and by 100% when both Pronase and hyaluronidase were added. The results suggested that the polysaccharides associated with the extracted soil oxidases protected the enzymes from proteolysis and may play a role in stabilizing exocellular enzymes in soils. 

Barthelmebs L., Divies, C. and Cavin, J.F. (2000) Knockout of the >-coumarate decarboxylase gene from Lactobacillus plantarum reveals the existence of two other inducible enzymatic activities involved in phenolic acid metabolism. Appl Environ Microbiol 66, 3368-3375. 

Precursors. Both hydroxycinnamic acids and 4-vinylphenols can lead to the formation of hydroxyphenyl-pyranoanthocyanins. The main hydroxycinnamic acids present in wines are p-coumaric, caffeic, ferulic and sinapic acids. 4-Vinylphenol and 4-vinylguaiacol are volatile phenols associated with off flavors in wine (Eti6vant 1981) and arise from the decarboxylation of p-coumaric and ferulic acid, respectively, via the yeast cinnamate decarboxylase (CD) (Chatonnet et al. 1993). 

In juices, prevention should be based on (i) decreasing the release of free acids that is favoured by mould infections of grapes and by the decarboxylase activity of commercial enzyme preparations and (ii) avoiding the production of volatile phenols that is favoured by the uncontrolled activity of contamination yeasts growing in damaged grapes or in juices. Then, the main measures to be adopted are ... 

Volatile phenols originate from hydroxycinnamic acids (ferulic, p-coumaric, or caffeic acid) by the action of hydroxycinnamate decarboxylase enzyme, which turn the hydroxycinnamics acid into vinylphe-nols (Albagnac, 1975 Grando et al., 1993). Then, these compounds are reduced to ethyl derivatives by vinylphenol reductase enzymes characteristic of species, such as Dekkera bruxellensis, Dekkera anomala, Pichia guillermondii, Candida versatilis, Candida halophila, and Candida mannitofaciens (Edlin et al., 1995 1998 Dias et al., 2003 Chatonnet et al., 1992 1995 1997 Dias et al., 2003), apart from very small quantities produced by some yeasts and lactic acid bacteria under peculiar growth conditions (Chatonnet et al., 1995 Barata et al., 2006 ... 

The cinnamate decarboxylase (CD) of Saccharomyces cerevisiae is highly specific. These yeasts are incapable of converting benzoic acids into volatile phenols. Only certain acids in the cinnamic series (phenyl-propenoic acids) may be decarboxylated by this microorganism. Among the cinnamic acids in grapes, only ferulic and p-coumaric acids are affected by the CD activity. Caffeic (4,5-dihydroxycinnamic) and sinapic (4-hydroxy-3,5-dimethoxycinnamic) acids are not decarboxylated by S. cerevisiae. Cinnamic acid and... 

The use of certain pectolytic enzyme preparations to facilitate the extraction or clarification of white must may lead to an increase in the vinyl-phenol content of white wines and a deterioration of their aromatic qualities (Chatonnet et al 1992a Dugelay etal., 1993 Barbe, 1995). Indeed, certain industrial pectinases, made from Aspergillus niger cultures, have a cinnamyl esterase (CE) activity. This enzyme catalyzes the hydrolysis of tartrate esters of hydroxycinnamic acids in must during the pre-fermentation phase (Figure 8.7). Feruhc and j9-coumaric acids are then converted into vinyl-phenols during alcohohc fermentation due to the cinnamate decarboxylase activity of Saccharomyces cerevisiae. 

A stndy of the mechanisms by which Brettanomyces biosynthesizes ethyl-phenols demonstrated the seqnential action of two enzymes (Figure 8.11). The first is a cinnamate decarboxylase that transforms cinnamic acids into vinyl-phenols. This enzyme, nnlike that of Saccha-romyces cerevisiae, is capable of decarboxylating... 

Caffeic Acid Phenethyl Ester (CAPE). CAPE, a phenolic compound with antioxidant properties, is an active ingredient derived from honeybee propolis (52). CAPE has antiviral, anti-inflammatory and antiproliferative properties. The compound differentially suppresses the growth of numerous human cancer cells and also inhibits tumor promoter-mediated processes in transformed cells (53,54). In transformed cells, CAPE induces apoptosis and inhibits the expression of the malignant phenotype (55,56). In addition, CAPE treatment attenuates the formation of azoxymethane-induced aberrant crypts and the activities of ornithine decarboxylase (ODC), tyrosin protein kinase, and lipoxygenase activity (57). Although the molecular basis for these multiple chemopreventive effects of CAPE is not clear, recent studies have demonstrated that CAPE is a potent and specific inhibitor of the transcription factor NF-kB (58). CAPE inhibited the activity and expression of COX-2 in the carrageenan air pouch model of inflammation as well as in TPA-treated human oral epithelial cells (59). CAPE was able to reduce neointimal formation by inhibiting NF-kB activation in a model of endothelial injury of rat carotid artery (60). 

It is believed that these compounds, characteristic of Brettanomyces and Dekkera, result from decarboxylation of hydroxycinnamic acids, yielding vinyl phenol intermediates and subsequent reduction to produce the ethyl analog (Steinke and Paulson, 1964). As seen in Fig. 3-3 initial decarboxylation is mediated by cinnamate decarboxylase, whereas the reduction step utilizes a vinyl phenol reductase. 

Rosemary (Rosmarinus officinalis) contains flavonoids, phenols, volatile oil and terpenoids. Topical application of rosemary extract, carnosol or ursolic acid to mouse skin inhibited the covalent binding of benzo[a]pyrene to epidermal DNA (Huang et al. 1994), tumour initiation by 7,12-dimethylbenz [ajanthracene (Singletary and Nelshoppen 1991), 12-0-tetradecano)dphorbol-13-acetate-induc-ed tumour promotion, ornithine decarboxylase (EC 4.1.1.17) activity and inflammation. Carnosol showed potent antioxidative activity in a,a-diphe-nyl-P-picrylhydrazyl free radicals scavenge and DNA protection from Fenton reaction (Lo et al. 2002). 

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