Molecular determinants of a selective matrix metalloprotease-12 inhibitor: insights from crystallography and thermodynamic studies.
The molecular determinants responsible for the potency of the RXP470.1 phosphinic peptide inhibitor toward matrix metalloprotease-12 (MMP-12) remain elusive. To address this issue, structure-activity study, X-ray crystallography, and isothermal titration calorimetry (ITC) experiments were performed. The crystal structure of MMP-12/inhibitor complex (1.15 Å) reveals that the inhibitor establishes multiple interactions with the MMP-12 active site, with its long P(1)' side chain filling most of the S(1)' deep cavity. ITC experiments indicate that the binding of this inhibitor to MMP-12 is mostly entropy driven (ΔG° = -13.1 kcal/mol, ΔH° = -2.53 kcal/mol, and -TΔS° = -10.60 kcal/mol) and involves a proton uptake from the buffer. Comparing phosphinic versus hydroxamate inhibitors reveals that the chelation of the zinc ion is slightly different, leading the inhibitor backbone to adopt a position in which the hydrogen bonding with the MMP-12 active site is less favorable in phosphinic inhibitor while maintaining high affinity.
CEA, Service d'Ingénierie Moléculaire des Protéines (SIMOPRO), Gif/Yvette 91191 Cedex, France.
Bertrand
B
Czarny
Enrico A
EA
Stura
Laurent
L
Devel
Laura
L
Vera
Evelyne
E
Cassar-Lajeunesse
Fabrice
F
Beau
Vito
V
Calderone
Marco
M
Fragai
Claudio
C
Luchinat
Vincent
V
Dive
D018360:Crystallography, X-Ray; D053508:Matrix Metalloproteinase 12 / Q000187:drug effects*; D008958:Models, Molecular; D011480:Protease Inhibitors / Q000737:chemistry / Q000494:pharmacology*; D013816:Thermodynamics
D011480:Protease Inhibitors; D053508:Matrix Metalloproteinase 12