STING agonist-4 is an stimulator of Interferon Genes (STING) receptor agonist with an apparent inhibitory constant (IC50) of 20 nM. STING agonist-4 is a two symmetry-related amidobenzimidazole (ABZI)-based compound to create linked ABZIs (diABZIs) with enhanced binding to STING and cellular function[1]. IC50: 20 nM (STING agonist-4)[1]
STING agonist-4 (Compound 2) (0.3-30 μM; 2 hours) causes phosphorylation of IRF3 and STING that is inhibited by the TBK1 inhibitor BX795 and induces dose-dependent secretion of IFN-β with an EC50 of 3.1 μM[1]. STING agonist-4 (Compound 2) (0.001 nM-1 μM) inhibits binding of full-length STING to the solid support with an apparent dissociation constant (Kd) of approximately 1.6 nM[1].STING agonist-4 (Compound 2) (0-100 μM) is 18-fold more potent than cGAMP (an endogenous STING ligand), with an EC50 of 53.9 μM[1]. STING agonist-4 (Compound 2) (3 μM; 4 hours) promotes production of interferon γ-induced protein 10 (IP-10), IL-6 and TNF-α by a mechanism that is dependent on STING-mediated activation of TBK1[1]. Cell Viability Assay[1] Cell Line: Human peripheral blood mononuclear cells (PBMCs)
[1]. Ramanjulu JM et al. Design of amidobenzimidazole STING receptor agonists with systemic activity. Nature. 2018 Dec;564(7736):439-443.