MOLECULAR MODELING OF LIPASE-CATALYZED POLYESTER SYNTHESIS

Molecular dynamics simulations and electrostatic potential calculation s were used to study the structure of a Rhizomucor miehei lipase (RmL) -substrate complex in a lipase catalyzed polyester synthesis. Two lipa se-substrate complexes were constructed with sebacic acid and 1,4-buty l sebacate as substrates, energy minimized, and simulated for 100 ps. During the simulation, catalytically important hydrogen bonds were for med more easily, when the acid was placed in the hydrophobic end and t he ester in the hydrophilic end of the active centre. However, also th e polarity of the active centre amino acids probably affects the place ment of the substrates. The electrostatic potential calculations showe d significant differences in the electrostatic potential of the surfac e of RmL. This may help the lipase to orientate itself appropriately f or the interfacial reaction. (C) 1997 Elsevier Science B.V.