Pyrimidine-Based Inhibitors of Dynamin I GTPase Activity: Competitive Inhibition at the Pleckstrin Homology Domain

The large GTPase
dynamin mediates membrane fission during clathrin-mediated
endocytosis (CME). The aminopyrimidine compounds were reported to
disrupt dynamin localization to the plasma membrane via the PH domain
and implicate this mechanism in the inhibition of CME. We have used
a computational approach of binding site identification, docking,
and interaction energy calculations to design and synthesize a new
library of aminopyrimidine analogues targeting site-2 of the pleckstrin
homology (PH) domain. The optimized analogues showed low micromolar
inhibition against both dynamin I (IC50 = 10.6 ± 1.3
to 1.6 ± 0.3 μM) and CME (IC50(CME) = 65.9 ±
7.7 to 3.7 ± 1.1 mM), which makes this series among the more
potent inhibitors of dynamin and CME yet reported. In CME and growth
inhibition cell-based assays, the data obtained was consistent with
dynamin inhibition. CEREP ExpresS profiling identified off-target
effects at the cholecystokinin, dopamine D2, histamine
H1 and H2, melanocortin, melatonin, muscarinic
M1 and M3, neurokinin, opioid KOP and serotonin
receptors.