SIB-1553A displaces the binding of nicotine (NIC) to the rat brain nAChRs with an IC50 value of 110 nM.
In calcium flux assays, SIB-1553A (0.1-5 μM), shows a greater selectivity for beta4-subunit containing recombinant hnAChRs (alpha2beta4, alpha3beta4 and alpha4beta4) vs. beta2-subunit containing nAChRs (alpha4beta2 and alpha3beta2) both in terms of efficacy and potency.