Investigation of lipases from various Carica papaya varieties for hydrolysis of olive oil and kinetic resolution of (R,S)-profen 2,2,2-trifluoroethyl thioesters
With olive oil hydrolysis in aqueous solutions and hydrolytic resolution of (R,S)-profen 2,2,2-trifluoroethyl thioesters in water-saturated isooctane as the model systems, the lipolysis and enantioselective hydrolysis activities of four partially purified Carica papaya lipases of different plant variety and geography location of cultures were compared to select pCPL-Indo from Indonesia as the best lipase preparation. For lipolysis, an optimal pH of 8.5 for all lipase preparations was found. Yet, pCPL-Indo possessed the highest activity at pH ranged from 7 to 10. For the kinetic resolution, the thermodynamic analysis implied that pCPL-Indo has changed the conformation at 60 °C and the enantiomer discrimination was dominated by ΔΔH. The kinetic analysis also indicated that the enantiomeric discrimination was mainly due to the difference of k2S and k2R in the acylation step. Agreements between experimental time-course conversions XS and best-fitted results were illustrated by considering effects of product inhibition and enzyme deactivation.
Journal: Process Biochemistry - Volume 41, Issue 3, March 2006, Pages 540–546