Résumé
Lipases/acyltransferases are unique enzymes that display the remarkable property to preferentially catalyze the transfer of a fatty acyl chain to other nucleophiles but water. This characteristic allows their usage for synthesis reactions in simple media comprising water as solvent and low amount of nucleophile acceptor such as alcohol. Moreover, under kinetical control, lipases/acyltransferases can allow to reach a reaction yield superior to that given by the thermodynamic equilibrium. Motivated by such features, studies were conducted to better understand the specific behavior of these enzymes, and focus was given to those related to the lipase/acyltransferase CpLIP2 from Candida parapsilosis and to the lipase A from Candida antarctica. The functional characterization of numerous homologous wild-type and modified lipases/acyltransferases has allowed to gain significant insights into the structure/function relationships of this original group of biocatalysts. In addition to being efficient for transesterification in lipid/water medium, they have shown interesting performances for diverse applications especially chemo-enzymatic in situ epoxidation.