Rapid screening for HIV-1 protease inhibitor leads through X-ray diffraction

Knowledge of the three-dimensional structures of HIV-1 protease and of its complexes with various inhibitors has played a key role in development of drugs against AIDS. Hexagonal crystals of unliganded tethered HIV-1 protease in which the enzyme conformation is identical to its ligand-bound state can be used in combination with the soaking method in order to identify potential inhibitor leads via X-ray diffraction. The advantages of the soaking method are the generality of application and the rapidity of structure determination for iterative structure-based drug design. Structures of two ligand complexes with HIV-1 protease determined using this method are shown to be very similar to the structures obtained earlier via co-crystallization.