|
KMID : 0545120180280122036
|
|
Journal of Microbiology and Biotechnology
2018 Volume.28 No. 12 p.2036 ~ p.2045
|
|
|
Roles of Carbohydrate-Binding Module (CBM) of an Endo-β-1,4-glucanase (Cel5L) from Bacillus sp. KD1014 in Thermostability and Small-Substrate Hydrolyzing Activity
|
|
Lee Jae-Pil
Shin Eun-Sun
Cho Min-Yeol
Lee Kyung-Dong
Kim Hoon
|
|
|
Abstract
|
|
|
|
An endo-β-1,4-glucanase gene, cel5L, was cloned using the shot-gun method from Bacillus sp.. The gene, which contained a predicted signal peptide, encoded a protein of 496 amino acid residues, and the molecular mass of the mature Cel5L was estimated to be 51.8 kDa. Cel5L contained a catalytic domain of glycoside hydrolase (GH) family 5 and a carbohydrate-binding module family 3 (CBM_3). Chromatography using HiTrap Q and CHT-II resulted in the isolation of two truncated forms corresponding to 50 (Cel5L-p50) and 35 kDa (Cel5L-p35, CBM_3-deleted form). Both enzymes were optimally active at pH 4.5 and 55°C, but had different half-lives of 4.0 and 22.8 min, respectively, at 70°C. The relative activities of Cel5L-p50 and Cel5L-p35 for barley β-glucan were 377.0 and 246.7%, respectively, compared to those for carboxymethyl-cellulose. The affinity and hydrolysis rate of pNPC by Cel5L-p35 were 1.7 and 3.3 times higher, respectively, than those by Cel5L-p50. Additions of each to a commercial enzyme set increased saccharification of pretreated rice straw powder by 17.5 and 21.0%, respectively. These results suggest CBM_3 is significantly contributing to thermostability, and to affinity and substrate specificity for small substrates, and that these two enzymes could be used as additives to enhance enzymatic saccharification.
|
|
|
KEYWORD
|
|
|
Bacillus sp. KD1014, GH5 endo-β-1,4-glucanase, truncated enzymes, CBM, thermostability, saccharification
|
|
|
FullTexts / Linksout information
|
|
|
|
|
|
Listed journal information
|
|
  
|
|