Fig. 1From: Marine-derived microbes and molecules for drug discoveryComparison between the interface of a conventional small molecule drug and its target enzyme and that of a biologic and its receptor. A Interaction between celecoxib, a conventional small molecule drug, and COX-2. Since the molecular weights of most conventional drugs are less than 500 Dalton, the interfaces between the small molecule drugs and their target proteins are relatively small. B Interaction between TNF-α and the extracellular domain of TNFR2. Since TNF-α is a proteinaceous ligand and the interface between TNF-α and one of its receptor TNFR2 is large, the inhibitors should be large enough to interfere with the PPIBack to article page