PMID: 26195137
Egbertson M, McGaughey GB, Pitzenberger SM, Stauffer SR, Coburn CA, Stachel SJ, Yang W, Barrow JC, Neilson LA, McWherter M, Perlow D, Fahr B, Munshi S, Allison TJ, Holloway K, Selnick HG, Yang Z, Swestock J, Simon AJ, Sankaranarayanan S, Colussi D, Tugusheva K, Lai MT, Pietrak B, Haugabook S, Jin L, Chen IW, Holahan M, Stranieri-Michener M, Cook JJ, Vacca J, Graham SL
Methyl-substitution of an iminohydantoin spiropiperidine beta-secretase (BACE-1) inhibitor has a profound effect on its potency.
Bioorg Med Chem Lett. 2015 Jun 29. pii: S0960-894X(15)00687-3. doi:, 10.1016/j.bmcl.2015.06.082.
The IC50 of a beta-secretase (BACE-1) lead compound was improved approximately 200-fold from 11muM to 55nM through the addition of a single methyl group. Computational chemistry, small molecule NMR, and protein crystallography capabilities were used to compare the solution conformation of the ligand under varying pH conditions to its conformation when bound in the active site. Chemical modification then explored available binding pockets adjacent to the ligand. A strategically placed methyl group not only maintained the required pKa of the piperidine nitrogen and filled a small hydrophobic pocket, but more importantly, stabilized the conformation best suited for optimized binding to the receptor.