Cutinases

What are Cutinases?

Cutinases, also known as cutin hydrolases, are enzymes first discovered in phytopathogenic fungi that grow on cutin as their sole carbon source. Cutin itself is a complex biopolymer made of hydroxy and epoxy fatty acids, forming the main component of the waxy cuticle that covers plant leaves, stems, and fruits. This protective layer prevents water loss and defends plants against pathogens, However, certain fungi have evolved cutinases to break it down. Belonging to the hydrolase family, cutinase catalyzes the hydrolysis of carboxylic acid ester bonds in cutin, producing alcohol and fatty acid monomers. Classified as an enzyme that targets ester bonds, it functions without the need for an oil-water interface, unlike most lipases, giving it exceptional versatility as a biocatalyst.

Biological Function and Role in Nature

In nature, cutinases play a large role in plant-pathogen interactions. Fungi such as Penicillium spinulosum and Nectria haematococca secrete cutinase to degrade the cuticle and invade plant tissue. Research shows that blocking cutinase activity can prevent infection, while adding the enzyme enhances it, suggesting it is essential in early infection stages. Although less studied, some bacteria like Thermobifida fusca and Pseudomonas putida also produce cutinas, sharing structural similarities with their fungal counterparts.

Structure of Cutinases

Structurally, cutinases belong to the alpha/beta-hydrolase fold family and contain a catalytic triad of serine, histidine, and aspartate. Unlike lipases, they lack a hydrophobic lid, leaving the active site exposed and functional in both aqueous and organic environments. During catalysis, histidine activates serine to attack the ester bond, leading to the release of alcohol and acid monomers. 

Industrial Applications

Cutinases’ adaptability makes them valuable in many industries, In detergents, they efficiently remove fatty stains from fabrics and remain stable at temperatures between 20 and 50 degrees celsius. In textiles and polymer processing, they can hydrolyze synthetic fibers like PET in an eco-friendly way. In the food and biofuel sectors, they can help break down fruit cuticles for faster drying and support transesterification reactions in biodiesel production. Their stability in organic solvents also enables applications in fine chemical synthesis and environmental cleanup.

Future Perspectives

Recent studies that identify bacterial cutinase genes, such as T.fusca’s Tfu_0882 and Tfu_0883, open new avenues for enzyme engineering. With their versatility, durability, and environmentally friendly nature, cutinases stand out as key players in advancing sustainable biotechnological processes.

References:

Chen, Sheng, et al. “Identification and Characterization of Bacterial Cutinase.” The Journal of Biological Chemistry, vol. 283, no. 38, 19 Sept. 2008, pp. 25854–25862, www.ncbi.nlm.nih.gov/pmc/articles/PMC3258855/, https://doi.org/10.1074/jbc.M800848200.

Martínez, Alejandro, and Sergi Maicas. “Cutinases: Characteristics and Insights in Industrial Production.” Catalysts, vol. 11, no. 10, 30 Sept. 2021, p. 1194, https://doi.org/10.3390/catal11101194.

Brinch-Pedersen, William, et al. “Discovery and Surface Charge Engineering of Fungal Cutinases for Enhanced Activity on Poly(Ethylene Terephthalate).” ACS Sustainable Chemistry & Engineering, vol. 12, no. 19, 27 Apr. 2024, pp. 7329–7337, https://doi.org/10.1021/acssuschemeng.4c00060. Accessed 9 Nov. 2025.

de, Damasceno, et al. “Evaluating Cutinase from Fusarium Oxysporum as a Biocatalyst for the Degradation of Nine Synthetic Polymer.” Scientific Reports, vol. 15, no. 1, 22 Jan. 2025, https://doi.org/10.1038/s41598-024-84718-0.

Schell, Kristina, et al. “Cutinases for Biocatalytic Polycarbonate Hydrolysis: Empowering Circular Economy.” ChemSusChem, vol. 18, no. 17, 3 June 2025, pp. e202500944–e202500944, https://doi.org/10.1002/cssc.202500944. Accessed 9 Nov. 2025.

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