title: Tailoring cutinase activity towards polyethylene terephthalate and polyamide 6,6 fibers.
abstract: Cutinase from Fusarium solani pisi was genetically modified near the active site, by site-directed mutagenesis, to enhance its activity towards polyethylene terephthalate (PET) and polyamide 6,6 (PA 6,6) fibers. The mutations L81A, N84A, L182A, V184A and L189A were done to enlarge the active site in order to better fit a larger polymer chain. Modeling studies have shown enhanced free energy stabilization of model substrate tetrahedral intermediate (TI) bound at the enzyme active site for all mutants, for both model polymers. L81A and L182A showed an activity increase of four- and five-fold, respectively, when compared with the wild type, for PET fibers. L182A showed the one- and two-fold higher ability to biodegrade aliphatic polyamide substrates. Further studies in aliphatic polyesters seem to indicate that cutinase has higher ability to recognize aliphatic substrates.
authors.affiliation: University of Minho, Textile Engineering Department, 4800-058 Guimarães, Portugal.
authors.forename: Rita
authors.initials: R
authors.lastname: Araújo
authors.forename: Carla
authors.initials: C
authors.lastname: Silva
authors.forename: Alexandre
authors.initials: A
authors.lastname: O'Neill
authors.forename: Nuno
authors.initials: N
authors.lastname: Micaelo
authors.forename: Georg
authors.initials: G
authors.lastname: Guebitz
authors.forename: Cláudio M
authors.initials: CM
authors.lastname: Soares
authors.forename: Margarida
authors.initials: M
authors.lastname: Casal
authors.forename: Artur
authors.initials: A
authors.lastname: Cavaco-Paulo
mesh_terms: D000327:Adsorption; D001711:Biotransformation; D002209:Caprolactam / Q000031:analogs & derivatives* / Q000737:chemistry / Q000378:metabolism; D002265:Carboxylic Ester Hydrolases / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D005670:Fusarium / Q000201:enzymology* / Q000378:metabolism; D008958:Models, Molecular; D016297:Mutagenesis, Site-Directed; D011093:Polyethylene Terephthalates / Q000737:chemistry / Q000378:metabolism*; D011108:Polymers / Q000737:chemistry / Q000378:metabolism*; D013386:Succinates / Q000378:metabolism
chemical_list: D011093:Polyethylene Terephthalates; D011108:Polymers; D013386:Succinates; C009916:nylon 6; D002209:Caprolactam; D002265:Carboxylic Ester Hydrolases; C019952:cutinase