Bioactive conformation of a potent stromelysin inhibitor determined by X-nucleus filtered and multidimensional NMR spectroscopy.

The biologically active conformation of a novel, very potent, nonpeptidic stromelysin inhibitor was determined by X-nucleus filtered and multidimensional NMR spectroscopy. This bound conformer was subsequently docked into the stromelysin catalytic domain (SCD) using intermolecular distance constraints derived from NOE data. The complex showed the S1' pocket of stromelysin to be the major site of enzyme-inhibitor interaction with other portions of the inhibitor spanning the S2' and S1 binding sites. Theoretical predictions of SCD-inhibitor binding from molecular modeling studies were consistent with the NMR data. Comparison of modeled enzyme-inhibitor complexes for stromelysin and collagenase revealed an alternate binding mode for the inhibitor in collagenase, suggesting a similar binding interaction might also be possible for stromelysin. The NMR results, however, revealed a single SCD-inhibitor binding mode and provided a structural template for the design of more potent stromelysin inhibitors.