Assay Method Information

Assay Name:  fluorescence polarization competition assay (FPCA)
Description:  Molecular modeling and SILCS functional group affinity mapping (FragMaps) of the Mcl-1 binding site indicated that the carboxylic acid of designed molecule 3a (FIG. 1C) would occupy an energetically favorable region, associated with a salt bridge interaction with R263 of the Mcl-1 binding site, while the ring of the naphthyl core would bind in the p3 pocket demarcated by a favorable non-polar FragMap. The aniline was directed into the hydrophobic p2 pocket, which is also demarcated by a nonpolar FragMap. With the molecular modeling data in hand, compound 3a was then synthesized according to Scheme 1-2.Briefly, commercially available 1-hydroxy-2-naphthoic acid (4) was regioselectively 4-chlorosulfonylated to yield 5, which was isolated by pouring over ice and used without further purification. Sulfonyl chloride 5 was next reacted with 4-bromoaniline to furnish the target molecule 3a in excellent overall yield (83%). Evaluation of 3a in a fluorescence polarization competition assay (FPCA) indicated that it disrupted the Mcl-1-Bak-BH3 PPI with an IC50 of 10.9 μM, corresponding to a Ki of 2.76 μM. Given the ability of 3a to inhibit Mcl-1, a structure-activity relationship (SAR) study was developed, the results of which are presented in the tables below.
Affinity data for this assay
 

If you find an error in this entry please send us an E-mail