|
KMID : 1007520000090030188
|
|
Food Science and Biotechnology
2000 Volume.9 No. 3 p.188 ~ p.194
|
|
|
Molecular Cloning and Characterization of a Thermostable Pullulanase from a Thermus Strain IM6501
|
|
Kim, Jung Wan
Park, Kwan Hwa/Kim, Tae Jip/Park, Woo Seok/Choi, Shin Kweon/Yoon, Young Jun
|
|
|
Abstract
|
|
|
|
A gene encoding a thermostable pullulanase was cloned from a thermophilic bacterial strain, Thermus IM6501. The Thermos pullulanase (TPL) gene encoded 718 residues for an enzyme with a molecular mass of 80 kDa. The enzyme was over expressed and purified by one-step procedure using a p6xHis119 expression vector in E. coli. The deduced amino acid sequence of TPL showed the four regions highly conserved among amylolytic enzymes. The enzyme was thermostable with an optimal temperature of 70℃, which was shifted to 75℃ in the presence of 1 mM CaCl₂. It was stable over a broad pH range of 5-10 with an optimum pH 6.0. TPL hydrolyzed pullulan solely to maltotriose by cleaving α-(1-6)-glycosidic linkage, indicating that it was a type I pullulanase.
|
|
|
KEYWORD
|
|
|
|
|
|
FullTexts / Linksout information
|
|
|
|
|
|
Listed journal information
|
|
 
|