[21] Stereoselectivity of lipase from Rhizopus oryzae toward triacylglycerols and analogs: Computer-aided modeling and experimental validation

Publisher Summary This chapter describes the preparation of Rhizopus oryzae lipase (ROL) from recombinant E. coli , the analysis of stereoselectivity of this lipase toward triacylglycerols and analogs, and computer modeling to gain insight into the molecular basis of its stereopreference. It is evident from the experimental data obtained in hydrolysis and esterification that the substituent in position sn-2 of the glycerol- or 1,3-propanediol backbone plays a crucial role in the stereoselectivity observed for ROL. It is noteworthy to mention that modulating polarity and flexibility of the sn-2 group not only affects the stereoselectivity expressed as enantiomeric excess, but also results in a reversal of stereopreference in hydrolysis. In esterification reactions the stereoselectivity increase concomitantly with a decrease of substrate polarity at the sn-2 position. However, no explanation can be provided for the different stereoselectivity in hydrolysis and esterification of substrates with 2-deoxy-2-alkyl group in sn-2 position.