Tailoring cutinase activity towards polyethylene terephthalate and polyamide 6,6 fibers.
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.
Araújo
Rita
R
University of Minho, Textile Engineering Department, 4800-058 Guimarães, Portugal.
Silva
Carla
C
O'Neill
Alexandre
A
Micaelo
Nuno
N
Guebitz
Georg
G
Soares
Cláudio M
CM
Casal
Margarida
M
Cavaco-Paulo
Artur
A
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
D011093:Polyethylene Terephthalates; D011108:Polymers; D013386:Succinates; C009916:nylon 6; D002209:Caprolactam; D002265:Carboxylic Ester Hydrolases; C019952:cutinase