Catalyzes the hydrolysis of complex carboxylic polyesters found in the cell wall of plants (Probable) (PubMed:12795380). Degrades cutin, a macromolecule that forms the structure of the plant cuticle (Probable) (PubMed:12795380). Allows pathogenic fungi to penetrate through the cuticular barrier into the host plant during the initial stage of fungal infection (Probable) (PubMed:12795380). cutin + H2O = cutin monomers. By contact with cutin. The 2 disulfide bonds play a critical role in holding the catalytic residues in juxta-position; reduction of the disulfide bridges results in the complete inactivation of the enzyme. Abolishes penetration of the host cuticle (PubMed:12795380). Abolishes conidiomata formation on the host (PubMed:12795380). Belongs to the cutinase family.