Chemical inhibitors of ExoC3L employ a variety of mechanisms to impede the protein's function. Benzyl isothiocyanate and Phenethyl isothiocyanate operate by covalently modifying cysteine residues within the ExoC3L active site, leading to a change in the protein's structure and an inhibition of its enzymatic activity. In a similar vein, allicin reacts with thiol groups on ExoC3L, which can result in the formation of disulfide bonds, potentially disrupting the protein's structure and function. Meanwhile, auranofin targets ExoC3L by irreversibly binding to thiol groups within the protein, thereby inhibiting its thiol-dependent enzymatic activity. Curcumin also exerts its inhibitory effect on ExoC3L by binding to the active site, thereby obstructing substrate access and disrupting enzymatic function. Similarly, capsaicin inhibits ExoC3L by altering the protein's tertiary structure or interfering with substrate access to the active site, leading to diminished enzymatic activity.
Other inhibitors, such as ebselen and oltipraz, modulate the activity of ExoC3L through indirect pathways. Ebselen mimics glutathione peroxidase activity, which can lead to the reduction of reactive oxygen species levels. This reduction can attenuate the signaling pathways necessary for ExoC3L optimal activity, resulting in its inhibition. Oltipraz, through its interaction with the Keap1-Nrf2 pathway, can alter cellular redox status, which, in turn, can inhibit ExoC3L function. Sulforaphane also activates the Nrf2 pathway, inducing the expression of detoxification and antioxidant enzymes that may interfere with ExoC3L function. Ellagic acid takes a different approach by chelating metal ions essential for ExoC3L's catalytic activity, thereby obstructing its enzymatic function. Finally, epigallocatechin gallate (EGCG) binds to ExoC3L and hinders its enzymatic function through hydrogen bonds and hydrophobic interactions, disrupting the normal activity of the protein.