title: Influence of organic co-solvents on the activity and substrate specificity of feruloyl esterases.
abstract: Organic co-solvents can expand the use of enzymes in lignocellulose deconstruction through making substrates more soluble and thus more accessible. In choosing the most adequate co-solvent for feruloyl esterases, hydrolysis of methyl p-hydroxycinnamates by three pure enzymes (and a multi-enzyme preparation) was evaluated. Low concentrations of dimethylsulfoxide (DMSO) enhanced hydrolysis by two of the enzymes while at levels >20%, activity was reduced. DMSO also enhanced acetyl esterase-type activity of the enzymes. The co-solvent effect was different for each enzyme-substrate couple, indicating that other factors are also involved. Kinetic studies with a Talaromyces stipitatus feruloyl esterase showed low concentrations of dimethylsulfoxide enhanced the hydrolytic rate while K(m) also increased. Moreover, long-term incubation (96 h) of an Aspergillus niger feruloyl esterase in dimethylsulfoxide:water provided to the enzyme the ability to hydrolyze methyl p-coumarate, suggesting an active-site re-arrangement. Dimethylsulfoxide (10-30%) is proposed as an adequate co-solvent for feruloyl esterase treatment of water-insoluble substrates.
authors.affiliation: Centro de Investigaciones Biológicas, Consejo Superior de Investigaciones Científicas, Ramiro de Maeztu 9, E-28040 Madrid, Spain. cfaulds@cib.csic.es
authors.forename: Craig B
authors.initials: CB
authors.lastname: Faulds
authors.forename: Marta
authors.initials: M
authors.lastname: Pérez-Boada
authors.forename: Angel T
authors.initials: AT
authors.lastname: Martínez
mesh_terms: D002265:Carboxylic Ester Hydrolases / Q000037:antagonists & inhibitors / Q000378:metabolism*; D007700:Kinetics; D009930:Organic Chemicals / Q000737:chemistry*; D012997:Solvents / Q000737:chemistry*; D013379:Substrate Specificity; D014783:Viscosity
chemical_list: D009930:Organic Chemicals; D012997:Solvents; D002265:Carboxylic Ester Hydrolases; C070196:feruloyl esterase