Gene cloning, expression, and characterization of phenolic acid decarboxylase from Lactobacillus brevis RM84

摘要

Phenolic acid decarboxylase (PAD) catalyzes\udthe synthesis of vinyl phenols from hydroxycinnamic acids.\udThe gene encoding PAD from Lactobacillus brevis was\udcloned and expressed as a fusion protein in Escherichia\udcoli. The recombinant PAD enzyme is a heat-labile enzyme\udthat functions optimally at 22 C and pH 6.0. The purified\udenzyme did not show thermostability at temperatures above\ud22 C. L. brevis PAD is able to decarboxylate exclusively\udthe hydroxycinnamic acids, such as p-coumaric, caffeic,\udand ferulic acids, with Km values of 0.98, 0.96, and\ud0.78 mM, respectively. The substrate specificity exhibited\udby L. brevis PAD is similar to the PAD isolated from\udBacillus subtilis and B. pumilus, but different from that of\udL. plantarum and Pediococcus pentosaceus. As the C-terminal\udregion may be involved in determining PAD substrate\udspecificity and catalytic capacity, amino acid\uddifferences among these proteins could explain the differences\udobserved. The substrate specificity shown by L.\udbrevis PAD shows promise for the synthesis of high-added\udvalue products from plant wastes