Expression and characterization of an extremely thermostable ß-glycosidase (mannosidase) from the hyperthermophilic archaeon Pyrococcus furiosus DSM3638.
N Biotechnol
; 28(6): 639-48, 2011 Oct.
Article
em En
| MEDLINE
| ID: mdl-21624508
ABSTRACT
Genomic analysis of the hyperthermophilic archaeon Pyrococcus furiosus revealed the presence of an open reading frame (ORF PF0356) similar to the enzymes in glycoside hydrolase family 1. This ß-glycosidase, designated PFTG (P. furiosus thermostable glycosidase), was cloned and expressed in Escherichia coli. The expressed enzyme was purified by heat treatment and Ni-NTA affinity chromatography. The gene was composed of 1,452 bp encoding 483 amino acids for a protein with a predicted molecular mass of 56,326 Da. The temperature and pH optima were 100°C and 5.0 in sodium citrate buffer, respectively. The substrate specificity of PFTG suggests that it possesses characteristics of both ß-galactosidase and ß-mannosidase activities. However, through kinetic studies by ITC (Isothermal Titration Colorimetry) which is very sensitive method for enzyme kinetics, PF0356 enzyme revealed the highest catalytic efficiency toward p-nitrophenyl-ß-d-mannopyranoside (3.02 k(cat)/K(m)) and mannobiose (4.32 k(cat)/K(m)). The enzyme showed transglycosylation and transgalactosylation activities toward cellobiose, lactose and mannooligosaccharides that could produce GOS (galactooligosaccharides) and MOS (maltooligosaccharides). This novel hyperthermostable ß-glycosidase may be useful for food and pharmaceutical applications.
Texto completo:
1
Coleções:
01-internacional
Contexto em Saúde:
3_ND
Base de dados:
MEDLINE
Assunto principal:
Proteínas Recombinantes
/
Expressão Gênica
/
Proteínas Arqueais
/
Pyrococcus furiosus
/
Manosidases
Tipo de estudo:
Prognostic_studies
Idioma:
En
Revista:
N Biotechnol
Ano de publicação:
2011
Tipo de documento:
Article