Purification and characterization of OXA-23 from Acinetobacter baumannii


Torol S., KASAP M.

JOURNAL OF ENZYME INHIBITION AND MEDICINAL CHEMISTRY, vol.28, no.4, pp.836-842, 2013 (Journal Indexed in SCI) identifier identifier identifier

  • Publication Type: Article / Article
  • Volume: 28 Issue: 4
  • Publication Date: 2013
  • Doi Number: 10.3109/14756366.2012.689296
  • Title of Journal : JOURNAL OF ENZYME INHIBITION AND MEDICINAL CHEMISTRY
  • Page Numbers: pp.836-842

Abstract

Although the existence of bla(OXA-23) is reported in various parts of the world, the product of bla(OXA-23) gene, OXA-23, has not been purified and its kinetic properties are not known. In this study, OXA-23 of Acinetobacter baumannii isolated from Kocaeli University intensive care unit was characterized after purification using recombinant methods. Preliminary results showed that conventional protein purification methods were not effective for purification of OXA-23. Therefore, OXA-23 was fused to maltose-binding protein of Escherichia coli, the fused protein was expressed and purified to homogeneity. Kinetic properties of the pure protein were then studied with substrates e. g., imipenem, meropenem, cefepime, ceftazidime, ampicilline, piperacillin, penicillin G, and nitrocefin. Also clavulanic acid, tazobactam, and sulbactam concentrations that inhibit 50% of OXA-23 enzyme activity were calculated. Modelling of OXA-23 revealed its ionic surface structure, conformation in the fused form and its topology allowing us to make predictions for OXA-23 substrate specificity.