Identification and characterization of a novel salt-tolerant esterase from a Tibetan glacier metagenomic library.
Biotechnol Prog
; 31(4): 890-9, 2015.
Article
in En
| MEDLINE
| ID: mdl-25920073
ABSTRACT
A salt-tolerant esterase, designated H9Est, was identified from a metagenomic library of the Karuola glacier. H9Est gene comprised 1071 bp and encoded a polypeptide of 357 amino acids with a molecular mass of 40 kDa. Sequence analysis revealed that H9Est belonged to the family IV of bacterial lypolitic enzyme. H9Est was overexpressed in Escherichia coli and the purified enzyme showed hydrolytic activity towards p-nitrophenyl esters with carbon chain from 2 to 8. The optimal esterase activity was at 40°C and pH 8.0 and the enzyme retained its activity towards some miscible organic solvents such as polyethylene glycol. A three-dimensional model of H9Est revealed that S200, D294, and H324 formed the H9Est catalytic triad. Circular Dichroism spectra and molecular dynamic simulation indicated that the esterase had a wide denaturation temperature range and flexible loops that would be beneficial for H9Est performance at low temperatures while retaining heat-resistant features.
Key words
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Ice Cover
/
Esterases
/
Metagenome
/
Salt Tolerance
Type of study:
Diagnostic_studies
Language:
En
Journal:
Biotechnol Prog
Journal subject:
BIOTECNOLOGIA
Year:
2015
Document type:
Article
Affiliation country:
Italy