Lactone ring-opening polymerization catalyzed by a Cutinase biocatalyst

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Mo Hunsen, Abul Azim, Harald Mang, Sabine R. Wallner, swallner@poly.edu, Asa Ronkvist, Wenchun Xie, wen4192001@yahoo.com, and Richard A. Gross, rgross@poly.edu. NSF I/UCRC for Biocatalysis and Bioprocessing of Macromolecules, Department of Chemical and Biological Sciences, Polytechnic University, 6 Metrotech Center, Brooklyn, NY 11201
Enzymes, predominantly lipases, are surprisingly active for a wide range of polyester and polycarbonate synthetic reactions. As part of our search for novel enzyme-catalysts for polymer synthesis, studies have begun on members of the cutinase family. Cutinases are extra-cellular fungal enzymes whose natural function is hydrolysis of cutin ester bonds. Cutin is the lipid-polyester that constitutes the outer shiny surface that protects leafs of higher plants. The cutinase from Humicola insolens was studied for lactone ring-opening polymerization reactions. Humicola insolens cutinase, immobilized on Lewatit, showed optimal activity at 70°C and is able to catalyze a broad range of lactone ring-opening polymerizations. Polyesters in high yield and with Mn values up to 45 000 g/mol were prepared by conducting reactions both in-bulk and in toluene solutions. This discovery paves the way for deeper investigations into new uses of cutinases as catalysts for non-natural polymerization reactions.