Partial purification and biochemical characterization of an extremely thermo- and pH-stable esterase with great substrate affinity

Authors

ESRA ÖZBEK
YAKUP KOLCUOĞLU
LEYLA KONAK
AHMET ÇOLAK
FULYA ÖZ

Abstract

An esterase from a thermophilic bacterium, Geobacillus sp. DF20, was partially purified. Final purification factor was found to be 64.5-fold using Q-Sepharose ion exchange column chromatography. Native polyacrylamide gel electrophoresis indicated the presence of a single active esterase. The substrate specificity of this esterase was high for p-nitrophenyl butyrate (pNPB) substrate. The optimum pH and temperature for the enzyme activity were 7.0 and 50 ^°C, respectively. The pH and heat stability profiles show that this enzyme is more stable under neutral conditions at 50 ^°C. K_m and V_{max} values for this esterase acting on pNPB were 0.12 mM and 54.6 U/mg protein, respectively. Presence of 10 % (v/v) acetonitrile in the reaction medium indicated that purified enzyme was strongly inhibited. It was also detected that some metal ions affected enzyme activity at different rates. As a result, it was observed that esterase from Geobacillus sp. DF20 has extreme temperature and pH stabilities. Therefore, the stability and K_m value of the enzyme make this study interesting when compared with the literature.

DOI

10.3906/kim-1308-23

Keywords

Thermophilic, esterase, Geobacillus sp., purification, pH stability

First Page

538

Last Page

546

Recommended Citation

ÖZBEK, ESRA; KOLCUOĞLU, YAKUP; KONAK, LEYLA; ÇOLAK, AHMET; and ÖZ, FULYA (2014) "Partial purification and biochemical characterization of an extremely thermo- and pH-stable esterase with great substrate affinity," Turkish Journal of Chemistry: Vol. 38: No. 4, Article 3. https://doi.org/10.3906/kim-1308-23
Available at: https://journals.tubitak.gov.tr/chem/vol38/iss4/3