초록
<P><B>Graphical abstract</B></P><P><ce:figure id='fig0005'></ce:figure></P><P><B>Highlights</B></P><P>► Ca<SUP>2+</SUP> activates the lipase activity in refolding buffer. ► Organic solvents assist the correct conformational transformation of the lipase. ► Water-immiscible organic solvents further improve the refolding of the lipase.</P> <P><B>Abstract</B></P><P>Expression of recombinant proteins as inclusion bodies in bacteria is one of the most efficient ways to produce cloned proteins, as long as the inclusion bodies can be successfully refolded. In this study, the different parameters were investigated and optimized on the refolding of denatured lipase. The maximum lipase activity of 5000U/L was obtained after incubation of denatured enzyme in a refolding buffer containing 20mM Tris–HCl (pH 7.0), 1mM Ca<SUP>2+</SUP> at 20°C. Then, the refolded lipase was purified to homogeneity by anion exchange chromatography. The purified refolded lipase was stable in broad ranges of temperatures and pH values, as well as in a series of water-miscible organic solvents. In addition, some water-immiscible organic solvents, such as petroleum ether and isopropyl ether, could reduce the polarity and increase the nonpolarity of the refolding system. The results of Fourier transform infrared (FT-IR) microspectroscopy were the first to confirm that lipase refolding could be further improved in the presence of organic solvents. The purified refolded lipase could enantioselectively hydrolyze <I>trans</I>-3-(4-methoxyphenyl) glycidic acid methyl ester [(±)-MPGM]. These features render the lipase attraction for biotechnological applications in the field of organic synthesis and pharmaceutical industry.</P>