Hydrolytic enzyme cutinase

The biopolymer cutin is a major constituent of the plant cuticle that provides a protective covering for plants (1,2). At the time of infection, a number of fungal pathogens secrete an extracellular hydrolytic enzyme, cutinase, which facilitates the degradation of cutin into its constituent Ci6-to Cig-length hydroxy fatty acids (3,4). Since the enzyme is believed to... 

Cutinase is a hydrolytic enzyme that degrades cutin, the cuticular polymer of higher plants [4], Unlike the oflier lipolytic enzymes, such lipases and esterases, cutinase does not require interfacial activation for substrate binding and activity. Cutinases have been largely exploited for esterification and transesterification in chemical synthesis [5] and have also been applied in laundry or dishwashing detergent [6]. 

Abstract The functionalization of synthetic polymers such as poly(ethylene terephthalate) to improve their hydrophilicity can be achieved biocatalytically using hydrolytic enzymes. A number of cutinases, lipases, and esterases active on polyethylene terephthalate have been identified and characterized. Enzymes from Fusarium solani, Thermomyces insolens, T. lanuginosus, Aspergillus oryzae, Pseudomonas mendocina, and Thermobifida fusca have been studied in detail. Thermostable biocatalysts hydrolyzing poly(ethylene terephthalate) are promising candidates for the further optimization of suitable biofunctionalization processes for textile finishing, technical, and biomedical applications. 

Alternatively, surface hydrolysis of PET can be achieved by treatment with enzymes that introduce polar groups to the polymer surface. A number of hydrolytic enzymes, such as lipases, cutinases, and esterases, have shown potential for surface functionalization of PET [36, 99]. The biocatalytic method can be performed under mild reaction conditions avoiding the use of large amounts of chemicals and energy for the finishing and dyeing processes. The enzymatic modifications are specific and can be limited to the polymer surface. Consequently, the bulk properties and mechanical stability of the polymer are not compromised, and material savings and products of better quality or with new functionalities can be obtained. 

This interfacial activation does not appear in all hydrolytic enzymes. For example, cutinase from fusarium solani, which hydrolyzes cutin, usually has the fatty acids -Ci6 and -C,8 and does not have a lid and does not exhibit these characteristics (Carvalho et al 1998 Schrag et al 1997). In addition, the presence of a lid does not always cause the enzyme to be active at the interface. The exception is lipase B from Candida antarctica that does not show interfacial activation despite having a lid (Kuo and Gardner, 2002 Uppenberg et al., 1994). Additionally, Staphylococcus hyicus and P. aeruginosa show an interfacial activation with some substrates but not with others (Verger, 1997). 

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