Purification and characterization of trans-3-(4-methoxyphenyl) glycidic acid methyl ester hydrolyzing lipase from Pseudomonas aeruginosa

Enantiospecific lipase was purified from Pseudomonas aeruginosa MTCC 5113 and it was used for the hydrolysis of (±)-methyl trans-3(4-methoxyphenyl) glycidate, a key intermediate in the synthesis of cardiovascular drug, diltiazem. Enzyme from broth supernatant was precipitated with acetone and purified by anion exchange and gel filtration chromatography. The purified lipase was a homogenous protein having a molecular weight of 59.4 kDa as determined by SDS-PAGE. Isoelectric point was found to be approximately 5.5 after 2D electrophoresis. This organic solvent tolerant enzyme was found to be active in presence of EDTA, Tween-80 and β-mercaptoethanol whereas sodium dodecyl sulphate and dithiothreitol inhibited its activity. The Km and Vmax of the enzyme were 50 mM and 27.1 μmol/min mg, respectively using p-nitrophenyl palmitate as a substrate. The activity of lipase was confirmed by (±)-MPGM hydrolysis and zymography.