10.15480/882.2239
Schröder, Carola
Carola
Schröder
1049357817
Blank, Saskia
Saskia
Blank
1047398028
Antranikian, Garabed
Garabed
Antranikian
109822382
First Glycoside Hydrolase Family 2 Enzymes from Thermus antranikianii and Thermus brockianus with β-Glucosidase Activity
Frontiers Media
2015
β-glucosidase
glycoside hydrolase
thermostable
thermus antranikianii
thermus brockianus
cellobiose
truncated domains
570: Biowissenschaften, Biologie
570
TUHH Universitätsbibliothek
TUHH Universitätsbibliothek
2019-05-07
2019-05-07
2015-06-03
en
Journal Article
Frontiers in bioengineering and biotechnology (3): 1-9 (2015)
2296-4185
http://hdl.handle.net/11420/2613
urn:nbn:de:gbv:830-882.034198
10.15480/882.2239
CC BY 4.0
Two glycoside hydrolase encoding genes (tagh2 and tbgh2) were identified from different Thermus species using functional screening. Based on amino acid similarities, the enzymes were predicted to belong to glycoside hydrolase (GH) family 2. Surprisingly, both enzymes (TaGH2 and TbGH2) showed twofold higher activities for the hydrolysis of nitrophenol-linked β-D-glucopyranoside than of -galactopyranoside. Specific activities of 3,966 U/mg for TaGH2 and 660 U/mg for TbGH2 were observed. In accordance, K m values for both enzymes were significantly lower when β-D-glucopyranoside was used as substrate. Furthermore, TaGH2 was able to hydrolyze cellobiose. TaGH2 and TbGH2 exhibited highest activity at 95 and 90°C at pH 6.5. Both enzymes were extremely thermostable and showed thermal activation up to 250% relative activity at temperatures of 50 and 60°C. Especially, TaGH2 displayed high tolerance toward numerous metal ions (Cu(2+), Co(2+), Zn(2+)), which are known as glycoside hydrolase inhibitors. In this study, the first thermoactive GH family 2 enzymes with β-glucosidase activity have been identified and characterized. The hydrolysis of cellobiose is a unique property of TaGH2 when compared to other enzymes of GH family 2. Our work contributes to a broader knowledge of substrate specificities in GH family 2.