Nonsteroidal anti-inflammatory drugs, such as aspirin, work by inhibiting the enzyme cyclooxygenase-2 (COX-2). Aspirin, however, can also bind to a similar enzyme, cyclooxygenase-1 (COX-1), causing stomach irritation and bleeding. Recently, the FDA has approved celecoxib, a much more selective inhibitor of COX-2 with little affinity for COX-1. The figure above shows a slice through a molecular model of COX-2 (green) containing a bound molecule of celecoxib (red). Superimposed with celecoxib is a modified form of the drug (modifications shown in blue) which has an even higher calculated affinity for COX-2 than celecoxib. The modified form was designed and tested during spring 1999 by an undergraduate student at Smith, Hibiki Kawamata, ('99). Modeling was performed using equipment and molecular modeling software (QUANTA) obtained through a Howard Hughes Medical Institute grant.
 

More comparison images of COX-1 and COX-2
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