Refolding of a recombinant organic solvent-stable lipase, which is overexpressed and forms an inclusion body, and activation with lipase-specific foldase

Overexpression of the organic solvent-stable LST-03 lipase from organic solvent-tolerant Pseudomonas aeruginosa LST-03 was attempted using a recombinant Escherichia coli system. It was achieved by deleting the signal peptide of the lipase and using T7 promoter. Although, the expressed lipase formed an inclusion body in E. coli, it was completely solubilized with 4 M urea and 0.05 mM dithiothreitol. The denaturants used for solubilization of the lipase inclusion body were easily removed by dilution or dialysis. The solubilized lipase was effectively activated by incubation with a lipase-specific foldase. The purity of the lipase recovered from the inclusion body was high. Use of a recombinant E. coli system improved the productivity of the highly pure lipase by about 807-fold, compared to the original system using P. aeruginosa LST-03.