Molecular modeling of ethyl oleate synthesis catalyzed by lipases from Candida rugosa and Candida antarctica B. Effect of structural water

MARÍA LAURA FORESTI; MARÍA LUJÁN FERREIRA

Málaga

Simposio; XXI Simposio Iberoamericano de Catálisis; 2008

Enzymatic esterification of oleic acid with ethanol was chosen as a model reaction of lipase-catalyzed fatty ester synthesis. Computational methods were applied in order to determine steric energies and enthalpic changes involved in each step of the mechanism of reaction. Molecular modeling results of the reaction catalyzed by lipases from Candida rugosa and Candida antarctica B were contrasted in order to infer weather diverse steric energy and enthalpic profiles may account for the differences in synthetic activity experimentally observed. The combined approach of molecular mechanics (MM2) and a semiempirical electronic method (PM3) used showed that reaction catalyzed by Candida antarctica B lipase is much more favorable in steric energy and enthalpic terms. Molecular modeling results also revealed that the presence of a molecule of water at the catalytic triad of lipases lowers the energy involved in each mechanistic step of the reaction considered.