AUTHOR=Guan Lijun , Wang Kunlun , Gao Yang , Li Jialei , Yan Song , Ji Nina , Ren Chuanying , Wang Jiayou , Zhou Ye , Li Bo , Lu Shuwen 

TITLE=Biochemical and Structural Characterization of a Novel Bacterial Tannase From Lachnospiraceae bacterium in Ruminant Gastrointestinal Tract

JOURNAL=Frontiers in Bioengineering and Biotechnology

VOLUME=Volume 9 - 2021

YEAR=2021

URL=https://www.frontiersin.org/journals/bioengineering-and-biotechnology/articles/10.3389/fbioe.2021.806788

DOI=10.3389/fbioe.2021.806788

ISSN=2296-4185

ABSTRACT=Tannases are a family of esterases that catalyze the hydrolysis of ester and depside bonds present in hydrolysable tannins to release gallic acid. Here, a novel tannase from Lachnospiraceae bacterium (TanALb) was characterized. The recombinant TanALb exhibited maximal activity at pH 7.0 and 50 °C, and it maintained more than 70% relative activity from 30 to 55 °C. The activity of TanALb was enhanced by Mg2+ and Ca2+, and was dramatically reduced by Cu2+ and Mn2+. TanALb TanALb is capable of degrading esters of phenolic acids with long chain alcohols such as lauryl gallate as well as tannic acid. The Km value and catalytic efficiency (kcat /Km) of TanALb towards 5 substrates showed that tannic acid (TA) was the favorite substrate. Homology modeling and structural analysis indicated that TanALb contains an insertion loop (residues 341-450). Based on the moleculer docking and MD simulation, this loop was observed as a flap-like lid to interact with bulk subtrates such as taninc acid. TanALb is a novel bacterial tannases, and the characteristics of this enzyme make it potentially interesting for industrial use.