caa a22 4500 605499136 CHVBK 20210128100549.0 cr unu---uuuuu 210128e20150301xx s 000 0 eng 10.1007/s00253-014-6085-9 doi (NATIONALLICENCE)springer-10.1007/s00253-014-6085-9 Characterization of a tannin acyl hydrolase from Streptomyces sviceus with substrate preference for digalloyl ester bonds [Elektronische Daten] [Mingbo Wu, Qin Wang, William McKinstry, Bin Ren] The search for new tannases with novel enzymatic properties suitable for industrial applications has been a continuous effort since the first discovery of the enzyme more than a century ago. A tannase gene (Ss-Tan) from the Gram-positive bacterium Streptomyces sviceus was identified, chemically synthesized, and cloned into a C-terminal His-tagged vector for expression in Escherichia coli. The tannase possesses the active site motif of GXSXG that is conserved for serine hydrolases. The residues that constitute the catalytic triad and galloyl binding site in bacterial tannases are found conserved in Ss-Tan, which include Ser209, Asp452, His484 and Lys370, Glu384, Asp454, respectively. Ss-Tan was overexpressed in E. coli BL21-AI cells with high productivity. Enzymatic assay revealed that the enzyme displays tannase activities to hydrolyze both the ester bonds and depside bonds in hydrolyzable tannins. Kinetic analysis indicated that the enzyme preferentially acts on depside bonds with considerably higher substrate affinity and catalytic efficiency. The enzyme showed maximum activity around pH 8.0 and at 50°C with the highest melting temperature close to 70°C. The high depsidase activity and thermostablility of Ss-Tan may make the enzyme suitable for potential industrial applications to achieve complete digestion of hydrolyzable tannins. Springer-Verlag Berlin Heidelberg, 2014 Tannase nationallicence Hydrolyzable tannin nationallicence Serine hydrolase nationallicence Streptomyces nationallicence Thermostability nationallicence Kinetics nationallicence Wu Mingbo Materials Science and Engineering, CSIRO, 343 Royal Parade, 3052, Parkville, VIC, Australia aut Wang Qin Institute of Nanobiomedical Technology and Membrane Biology, State Key Laboratory of Biotherapy, Sichuan University, 610041, Chengdu, China aut McKinstry William Materials Science and Engineering, CSIRO, 343 Royal Parade, 3052, Parkville, VIC, Australia aut Ren Bin Materials Science and Engineering, CSIRO, 343 Royal Parade, 3052, Parkville, VIC, Australia aut Applied Microbiology and Biotechnology Springer Berlin Heidelberg 99/6(2015-03-01), 2663-2672 0175-7598 99:6<2663 2015 99 253 https://doi.org/10.1007/s00253-014-6085-9 text/html Onlinezugriff via DOI BK010053 XK010053 XK010000 Metadata rights reserved Springer special CC-BY-NC licence nationallicence 1 research-article jats NATIONALLICENCE NATIONALLICENCE NL-springer NATIONALLICENCE 856 40 https://doi.org/10.1007/s00253-014-6085-9 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Wu Mingbo Materials Science and Engineering, CSIRO, 343 Royal Parade, 3052, Parkville, VIC, Australia aut NATIONALLICENCE 700 1- Wang Qin Institute of Nanobiomedical Technology and Membrane Biology, State Key Laboratory of Biotherapy, Sichuan University, 610041, Chengdu, China aut NATIONALLICENCE 700 1- McKinstry William Materials Science and Engineering, CSIRO, 343 Royal Parade, 3052, Parkville, VIC, Australia aut NATIONALLICENCE 700 1- Ren Bin Materials Science and Engineering, CSIRO, 343 Royal Parade, 3052, Parkville, VIC, Australia aut NATIONALLICENCE 773 0- Applied Microbiology and Biotechnology Springer Berlin Heidelberg 99/6(2015-03-01), 2663-2672 0175-7598 99:6<2663 2015 99 253