||4IJO deposited: 2012-12-22 modified: 2013-07-31
||Unraveling hidden allosteric regulatory sites in structurally homologues metalloproteases
||Arad-Yellin, R., Berezovsky, I.N., Calderone, V., Fragai, M., Grossman, M., Luchinat, C., Melikian, M., Mitternacht, S., Sagi, I., Toccafondi, M., Udi, Y.
||resolution 1.9 rfactor 0.18327 rfree 0.23194
theoretical min: 0.16
|Related PDB Entries
Monitoring enzymatic activity in vivo of individual homologous enzymes such as the matrix metalloproteinases (MMPs) by antagonist molecules is highly desired for defining physiological and pathophysiological pathways. However, the rational design of antagonists targeting enzyme catalytic moieties specific to one of the homologous enzymes often appears to be an extremely difficult task. This is mainly due to the high structural homology at the enzyme active sites shared by members of the protein family. Accordingly, controlling enzymatic activity via alternative allosteric sites has become an attractive proposition for drug design targeting individual homologous enzymes. Yet, the challenge remains to identify such regulatory alternative sites that are often hidden and scattered over different locations on the protein's surface. We have designed branched amphiphilic molecules exhibiting specific inhibitory activity towards individual members of the MMP family. These amphiphilic isomers share the same chemical nature, providing versatile nonspecific binding reactivity that allows to probe hidden regulatory residues on a given protein surface. Using the advantage provided by amphiphilic ligands, here we explore a new approach for determining hidden regulatory sites. This approach includes diverse experimental analysis, such as structural spectroscopic analyses, NMR, and protein crystallography combined with computational prediction of effector binding sites. We demonstrate how our approach works by analyzing members of the MMP family that possess a unique set of such sites. Our work provides a proof of principle for using ligand effectors to unravel hidden regulatory sites specific to members of the structurally homologous MMP family. This approach may be exploited for the design of novel molecular effectors and therapeutic agents affecting protein catalytic function via interactions with structure-specific regulatory sites.
J.Mol.Biol. 2013 Jul; 425(13):2330-2346 doi:10.1016/j.jmb.2013.04.009
ANGEW.CHEM.INT.ED.ENGL. 2006 Dec; 45(47):7952-7955 doi:10.1002/anie.200603100
"The structures of the catalytic domain of matrix metalloproteinase 12 in the presence of acetohydroxamic acid and N-isobutyl-N-[4-methoxyphenylsulfonyl]glycyl hydroxamic acid have been solved by x-ray diffraction in the crystalline state at 1.0 and 1.3-A resolution, respectively, and compared with the previously published x-ray structure at 1.2-A resolution of the adduct with batimastat. The structure of the N-isobutyl-N-[4-methoxyphenylsulfonyl]glycyl hydroxamic acid adduct has been solved by NMR in solution. The three x-ray structures and the solution structure are similar but not identical to one another, the differences being sizably higher in the loops. We propose that many of the loops show a dynamical behavior in solution on a variety of time scales. Different conformations of some flexible regions of the protein can be observed as ""frozen"" in different crystalline environments. The mobility in solution studied by NMR reveals conformational equilibria in accessible time scales, i.e., from 10(-5) s to ms and more. Averaging of some residual dipolar couplings is consistent with further motions down to 10(-9) s. Finally, local thermal motions of each frozen conformation in the crystalline state at 100 K correlate well with local motions on the picosecond time scale. Flexibility/conformational heterogeneity in crucial parts of the catalytic domain is a rule rather than an exception in matrix metalloproteinases, and its extent may be underestimated by inspection of one x-ray structure. Backbone flexibility may play a role in the difficulties encountered in the design of selective inhibitors, whereas it may be a requisite for substrate binding and broad substrate specificity."
Proc.Natl.Acad.Sci.Usa 2005 Apr; 102(15):5334-5339 doi:10.1073/pnas.0407106102