Product Code Database
The enzyme cutinase (systematic name: cutin hydrolase, EC 3.1.1.74) is a member of the Hydrolase. It Catalysis the following reaction:
In biological systems, the reactant carboxylic ester is a constituent of the cutin polymer, and the hydrolysis of cutin results in the formation of alcohol and carboxylic acid monomer products.
Research suggests that cutin plays a critical role in preventing infections in plant systems. For instance, experiments conducted on tomato plants that had a substantial inability to synthesize cutin found that the tomatoes produced by those plants were significantly more susceptible to infection by both opportunistic pathogens and intentionally inoculated Fungus .;
Cutinase is produced by a variety of fungal plant pathogens, and its activity was first detected in the fungus, Penicillium spinulosum. In studies of Nectria haematococca, a fungal pathogen that is the cause of foot rot in pea plants, cutinase has been shown to play key roles in facilitating the early stages of plant infection. It is also suggested that fungal spores that make initial contact with plant surfaces, a small amount of catalytic cutinase produces cutin monomers which in turn up-regulate the expression of the cutinase gene. This proposes that the expression pathway of cutinase in fungal spores is characterized by a positive feedback loop until the fungus successfully breaches the cutin layer; however, the specific mechanism of this pathway is unclear. Inhibition of cutinase has been shown to prevent fungal infection through intact cuticles. Conversely, the supplementation of cutinase to fungi that are not able to produce it naturally had been shown to enhance fungal infection success rates.
Cutinases have also been observed in a few plant pathogenic species, such as Streptomyces scabies, Thermobifida fusca, Pseudomonas mendocina, and Pseudomonas putida, but these have not been studied to the extent as those found in fungi. The molecular structure of the Thermobifida fusca cutinase shows similarities to the Fusarium solani pisi fungal cutinase, with congruencies in their active sites and overall mechanisms.
Crystal structures have shown that the active site of cutinases is found on one end of the ellipsoid shape of the enzyme. This active site is seen flanked by two Hydrophobe loop structures and partly covered by 2 thin bridges formed by amino acid side chains. It does not possess a hydrophobic lid, which is a common constituent feature among other . Instead, the catalytic serine in the active site is exposed to open solvent, and the cutinase enzyme does not show interfacial activation behaviors at an aqueous-nonpolar interface. Cutinase activation is believed to be derived from slight shifts in the conformation of hydrophobic residues, acting as a miniature lid. The oxyanion hole in the active site is a constituent feature of the binding site, which differs from most lipolytic enzymes whose oxyanion holes are induced upon substrate binding.
Rather unexpectedly, the ability to degrade the cutin layer of plants and their fruits holds the potential to be beneficial to the fruit industry. This is because the cuticle layer of fruits is a putative mechanism of water regulation, and the degradation of this layer subjects the fruits to water movement across its membrane. By using cutinase to degrade the cuticle of fruits, industry makers can enhance the drying of fruits and more easily deliver preservatives and additives to the flesh of the fruit.
|
|
