Angstrom: Scouring the surface

By Kathryn Calkins

Staff Writer When choosing molecular targets for drug design, companies often try to pick ones such as enzymes or nuclear receptors that have small, well-defined active sites that can make drug design simpler. Such targets, however, harbor their own set of design problems, because they are found inside cells, where delivery can be an issue. Too often, the outer cell membrane is an impenetrable barrier to the drug. And even if it isn't, trying to factor in membrane permeability properties can put limits on the drug design process...