|
KMID : 0545120000100050638
|
|
Journal of Microbiology and Biotechnology
2000 Volume.10 No. 5 p.638 ~ p.642
|
|
|
Purification and Characterization of a Thermostable B-Glycosidase from Thermus caldophilus GK24
|
|
Yoo, Jin Sang
Han, Ki Woong/Kim, Hyun Kyu/Kim, Min Hong/Kwon, Suk Tae
|
|
|
Abstract
|
|
|
|
A β-glycosidase enzyme with β-D-fucosidase, β-D-galactosidase, and β-D-glucosidase activities has been purified from Thermus caldophilus GK24. The enzyme was monomeric with a molecular mass of 49kDa, as evidenced by SDSPAGE. The K_m values for p-nitrophenyl β-D-fucopyranoside (p-NPFuc), p-nitrophenyl β-D-galactopyranoside (p-NPGa1), and p-nitrophenyl β-D-glucopyranoside (p-NPGlu) were 0.23mM, 6.25mM, and 0.28mM, respectively. The enzyme showed optimal pH ranging between 5.5-6.5 and maximum temperature in the range of 85-90℃ for all the above mentioned activities. The half-life of the enzyme in sodium phosphate buffer (pH 6.0) at 80℃ was approximately 7h. The p-NPGal hydrolyzing activity of Tca β-glycosidase was strongly activated by Lhistidine, while the p-NPFuc and p-NPGlu hydrolyzing activities of Tca β-glycosidase were not affected at all by the amino acid. These results suggest differences in the conformation or in the reactive residues at the active site of Tca β-glycosidase.
|
|
|
KEYWORD
|
|
|
|
|
|
FullTexts / Linksout information
|
|
|
|
|
|
Listed journal information
|
|
  
|
|