An endogenous factor enhances ferulic acid decarboxylation catalyzed by phenolic acid decarboxylase from Candida guilliermondii

Hui-Kai Huang,Tadahiro Ozawa,Toki Taira,Li-Fan Chen,Masamichi Tokashiki,Susumu Ito

doi:10.1186/2191-0855-2-4

Hui-Kai Huang, Tadahiro Ozawa + Show 4 more

Open Access

https://doi.org/10.1186/2191-0855-2-4

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Abstract

The gene for a eukaryotic phenolic acid decarboxylase of Candida guilliermondii was cloned, sequenced, and expressed in Escherichia coli for the first time. The structural gene contained an open reading frame of 504 bp, corresponding to 168 amino acids with a calculated molecular mass of 19,828 Da. The deduced amino sequence exhibited low similarity to those of functional phenolic acid decarboxylases previously reported from bacteria with 25-39% identity and to those of PAD1 and FDC1 proteins from Saccharomyces cerevisiae with less than 14% identity. The C. guilliermondii phenolic acid decarboxylase converted the main substrates ferulic acid and p-coumaric acid to the respective corresponding products. Surprisingly, the ultrafiltrate (Mr 10,000-cut-off) of the cell-free extract of C. guilliermondii remarkably activated the ferulic acid decarboxylation by the purified enzyme, whereas it was almost without effect on the p-coumaric acid decarboxylation. Gel-filtration chromatography of the ultrafiltrate suggested that an endogenous amino thiol-like compound with a molecular weight greater than Mr 1,400 was responsible for the activation.

Highlights

Ferulic acid (FA), a derivative of 4-hydroxycinnamic acid, is found in cell walls primarily as an ester linked to lignin and other polysaccharides in cell walls, leaves and seeds of plants such as in rice, wheat, and oat [Mathew and Abraham 2004]
CgPAD was active toward 4-hydroxycinnamic acid derivatives, p-coumaric acid (PCA), FA, and caffeic acid (CA), whose relative activity ratios are different from the phenolic acid decarboxylases (PADs) of B. anomalus and B. bruxellensis
We found that the presence of dithiothreitol (DTT), 2-mercaptoethanol, cysteine, and homocysteine considerably accelerated the rates of FA decarboxylation activity of the purified native and recombinant CgPAD, while they did not affect those of their PCA decarboxylation activity

Summary

Introduction

Ferulic acid (FA), a derivative of 4-hydroxycinnamic acid, is found in cell walls primarily as an ester linked to lignin and other polysaccharides in cell walls, leaves and seeds of plants such as in rice, wheat, and oat [Mathew and Abraham 2004]. The genetic mechanism of bacterial PAD expression has been well established by the Naturally-occurring phenolic acids are known to inhibit the growth of yeasts such as Saccharomyces cerevisiae, Pichia anomala, Debaryomyces hansenii, and Candida guilliermondii S. cerevisiae [Goodey and Tubb 1982,Clausen et al 1994,Smit et al 2003,Coghe et al 2004], Brettanomyces bruxellensis [Godoy et al 2008], and C. guilliermondii [Huang et al.2011] are suggested to produce a PAD in response or relation to 4-hydroxycinnamic acids. CgPAD was active toward 4-hydroxycinnamic acid derivatives, PCA, FA, and CA, whose relative activity ratios are different from the PADs of B. anomalus and B. bruxellensis

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