Purification and characterization of a halophilic urethanase from Klebsiella pneumoniae / 生物工程学报
Chinese Journal of Biotechnology
;
(12): 404-411, 2014.
Article
in Chinese
| WPRIM
| ID: wpr-279509
ABSTRACT
Ethyl carbamate (EC) is a carcinogenic substance in many fermented foods. Enzymatic removal of ethyl carbamate from fermented foods is an important way to eliminate its potential health damage to consumers. To study the enzymatic properties of an ethyl carbamate hydrolase (urethanase) from Klebsiella pneumoniae, a strain isolated from murine somach, we purified the enzyme using ammonium sulfate precipitation, ion exchange chromatography and gel filtration chromatography. The molecular mass of this enzyme was estimated to be 55 kDa by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). Its K(m) was 74 mmol/L when EC was used as the substrate. Moreover, its optimal reaction temperature was 55 degrees C, and the optimum pH was 7.0. The activity was enhanced by ethylene diamine tetraacetic acid (EDTA) and dithiothreitol (DTT), but strongly inhibited by Cu2+ and Zn2+. The enzyme was halophilic and tolerant to low concentration of ethanol. Therefore, it has the potential to remove EC from fermented foods.
Full text:
Available
Index:
WPRIM (Western Pacific)
Main subject:
Substrate Specificity
/
Temperature
/
Bacterial Proteins
/
Chemistry
/
Chromatography, Gel
/
Chromatography, Ion Exchange
/
Electrophoresis, Polyacrylamide Gel
/
Amidohydrolases
/
Hydrogen-Ion Concentration
/
Klebsiella pneumoniae
Language:
Chinese
Journal:
Chinese Journal of Biotechnology
Year:
2014
Type:
Article
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