ART2 Inhibitors

Chemical inhibitors of ART2 function by obstructing the protein's interaction with its substrates and influencing the extracellular environment to which ART2 is exposed. Suramin is a multifaceted inhibitor that can directly bind to ART2, preventing the protein from interacting with extracellular ATP, which is necessary for its enzymatic action of ADP-ribosylation. This blockage directly inhibits the catalytic activity of ART2. Reactive Blue 2 and Brilliant Blue G serve as antagonists to P2 receptors, which play a role in the regulation of extracellular nucleotide concentrations. By antagonizing these receptors, these dyes reduce the levels of extracellular nucleotides, limiting the availability of ART2's substrates, and as a result, its activity is diminished. ARL 67156, by inhibiting ecto-ATPases, can increase extracellular ATP concentrations, leading to the saturation of ART2 and indirectly inhibiting its ADP-ribosylation function. Oxidized ATP, through the irreversible inhibition of P2X7 receptors, can decrease ATP-mediated responses, thereby reducing the activity of ART2 by altering the extracellular nucleotide pool.

Additionally, PPADS and MRS2179 selectively antagonize P2 receptors, which are instrumental in controlling the extracellular levels of nucleotides such as ATP; by competing with nucleotides for receptor binding, they lower extracellular nucleotide levels and indirectly inhibit ART2's ability to modify target proteins through ADP-ribosylation. KN-62 targets intracellular signaling by inhibiting Ca2+/calmodulin-dependent protein kinases, which are involved in the signaling pathways that can facilitate ART2 activity; by inhibiting these kinases, KN-62 can decrease ART2's functional output. NF023, as a selective inhibitor of specific P2 receptor subtypes, can lead to a reduction in extracellular nucleotide concentrations, thereby indirectly inhibiting ART2. Similarly, TNP-ATP acts as a potent P2 receptor antagonist, which can lower extracellular ATP levels, indirectly inhibiting ART2 by reducing the substrate necessary for ART2 activity. Pyridoxal-phosphate-6-azophenyl-2',4'-disulfonic acid inhibits P2 receptors and consequently decreases the extracellular pool of ATP, which is essential for ART2's activity in ADP-ribosylation of target proteins.