FIGURE 1.

Aggregating promiscuous inhibitors have characteristic physical features and behaviors that distinguish them from classical inhibitors. Their distinct physical properties lend themselves to detection by direct biophysical measurement of particle size and shape; their presence is often indicated by steep dose-response curves. (a) Particle formation by the promiscuous inhibitor tetraiodophenolphthalein, as visualized by transmission electron microscopy (Bar = 100 nm) and (b) by dynamic light scattering. (c) The dose-response curve of Rottlerin, a promiscuous inhibitor at micromolar concentrations (circles) compared to that of BZB, a pure competitive inhibitor (squares), both acting against the enzyme β-lactamase. Reprinted, with permission, from Refs. [8] and [13].