NMR solution structure of the catalytic fragment of human fibroblast collagenase complexed with a sulfonamide derivative of a hydroxamic acid compound

The solution structure of the catalytic fragment of human fibroblast collag enase (MMP-1) complexed with a sulfonamide derivative of a hydroxamic acid compound (CGS-27023A) has been determined using two-dimensional and three-d imensional heteronuclear NMR spectroscopy. The solution structure of the co mplex was calculated by means of hybrid distance geometry-simulated anneali ng using a combination of experimental NMR restraints obtained from the pre vious refinement of the inhibitor-free MMP-1 (1) and recent restraints for the MMP-1:CGS-27023A complex. The hydroxamic acid moiety of CGS-27023A was found to chelate to the "right" of the catalytic zinc where the p-methoxyph enyl sits in the S1' active-site pocket, the isopropyl group is in contact with H83 and N80, and the pyridine ring is solvent exposed. The sulfonyl ox ygens are in hydrogen-bonding distance to the backbone NHs of L81 and A82, This is similar to the conformation determined by NMR of the inhibitor boun d to stromelysin (2, 3), A total of 48 distance restraints were observed be tween MMP-1 and CGS-27023A from 3D C-13- edited/C-12-filtered NOESY and 3D N-15-edited NOESY experiments. An additional 18 intramolecular restraints w ere observed for CGS-27023A from a 2D C-12-filtered NOESY experiment, A min imal set of NMR experiments in combination with the free MMP-1 assignments were used to assign the MMP-1 H-1, C-13, and N-15 resonances in the MMP-1:C GS-27023A complex. The assignments of CGS-27023A in the complex were obtain ed from 2D C-12-filtered NOESY and 2D C-12-filtered TOCSY experiments.