Recombinant cyclodextrinase from Thermococcus kodakarensis KOD1: expression, purification, and enzymatic characterization.
Archaea
; 2015: 397924, 2015.
Article
em En
| MEDLINE
| ID: mdl-25688178
ABSTRACT
A gene encoding a cyclodextrinase from Thermococcus kodakarensis KOD1 (CDase-Tk) was identified and characterized. The gene encodes a protein of 656 amino acid residues with a molecular mass of 76.4 kDa harboring four conserved regions found in all members of the α-amylase family. A recombinant form of the enzyme was purified by ion-exchange chromatography, and its catalytic properties were examined. The enzyme was active in a broad range of pH conditions (pHs 4.0-10.0), with an optimal pH of 7.5 and a temperature optimum of 65°C. The purified enzyme preferred to hydrolyze ß-cyclodextrin (CD) but not α- or γ-CD, soluble starch, or pullulan. The final product from ß-CD was glucose. The V max and K m values were 3.13 ± 0.47 U mg(-1) and 2.94 ± 0.16 mg mL(-1) for ß-CD. The unique characteristics of CDase-Tk with a low catalytic temperature and substrate specificity are discussed, and the starch utilization pathway in a broad range of temperatures is also proposed.
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1
Base de dados:
MEDLINE
Assunto principal:
Thermococcus
/
Glicosídeo Hidrolases
Idioma:
En
Ano de publicação:
2015
Tipo de documento:
Article