Kinase experiment:

RAW 264.7 cells are planted in 6-well plates at 1,000,000 cells per well with 3 mL of medium and grown for 24 h at 37℃ in a 5% CO2 humidified incubator. After 24 h, non-adherent cells and media are removed and replaced with fresh RPMI 1640 medium (3 mL/well). Two wells of adherent macrophages are treated with Pam3CSK4 (300 ng/mL) as the positive control, two wells are treated with 8 μM CU-CPT22, and the other two wells are treated with 8 μM compound DMSO. Plates are then incubated for an additional 24 h. The medium is removed, the cells are washed with PBS (3×1 mL), the plate is put on ice, then 500 μL of lysis buffer is added to each well. The production of the cytokine interleukin-1β (IL-1β) and TNF-α is quantified with enzyme-linked immunosorbent assays (ELISA). The cytokine level in each sample is determined in duplicate[1].

CU-CPT22 is a potent protein complex of toll-like receptor 1 and 2 (TLR1/2) inhibitor, and competes with the synthetic triacylated lipoprotein (Pam3CSK4) binding to TLR1/2 with a Ki of 0.41 μM. CU-CPT22 blocks Pam3CSK4-induced TLR1/2 activation with an IC50 of 0.58 μM[1].

CU-CPT22 is a toll-like receptor 1 and 2 (TLR1/2) inhibitor with an IC50 of 0.58±0.09 μM. It is demonstrated that CU-CPT22 is able to compete with Pam3CSK4 for binding to TLR1/2 with an inhibition constant (Ki) of 0.41±0.07 μM, which is consistent with its potency observed in the whole cell assay. Increasing the concentration of CU-CPT22 to 6 μM decreases the anisotropy to background levels. It is found that CU-CPT22 inhibits TLR1/2 signaling without affecting other TLRs, showing it is highly selective in intact cells. CU-CPT22 is found to have no significant cytotoxicity at various concentrations up to 100 μM in RAW 264.7 cells. The result demonstrates that CU-CPT22 can inhibit about 60% of TNF-αand 95% of IL-1β at 8 μM[1].

References:
[1]. Cheng K, et al. Discovery of small-molecule inhibitors of the TLR1/TLR2 complex. Angew Chem Int Ed Engl. 2012 Dec 3;51(49):12246-9.