title: The collagenolytic action of MMP-1 is regulated by the interaction between the catalytic domain and the hinge region.
abstract: The role of the hinge region in the unwinding and cleavage of type I collagen by interstitial collagenase (MMP-1) has been studied at 37 °C and pH 7.3. The collagenolytic processing by MMP-1 displays a very similar overall rate for both chains of collagen I, even though the affinity is higher for the α-1 chain and the cleavage rate is faster for the α-2 chain. MMP-1 binding to collagen I brings about a significant unwinding of the triple-helical arrangement only after the first cleavage step of the α-1 and α-2 chains. The proteolytic processing by wild-type MMP-1 on a synthetic substrate and collagen I has been compared with that observed for site-directed mutants obtained either by truncating the hinge region (∆255-272) or by individually replacing the conserved amino acids Val268, Gly272, and Lys277 of the hinge region with residues observed for the corresponding position in stromelysin-1 (MMP-3), a noncollagenolytic metalloproteinase. The ∆256-272 mutant has no collagenolytic activity, clearly demonstrating the crucial role of this region for the enzymatic processing of collagen I. However, among various mutants investigated, only Gly272Asp shows a dramatically reduced enzymatic activity both on the synthetic substrate and on collagen I. This effect, however, is clearly related to the substituting residue, since substitution of Ala or Asn for Gly272 does not have any effect on the kinetic properties of MMP-1. These data suggest that the substrate specificity of MMP-1 is dictated by the reciprocal structural relationships between the catalytic domain and the carboxy-terminal domain through the conformational arrangement of the hinge region.
authors.affiliation: Department of Clinical Sciences and Translational Medicine, University of Roma Tor Vergata, Via Montpellier 1, 00133 Rome, Italy.
authors.forename: Giovanni Francesco
authors.initials: GF
authors.lastname: Fasciglione
authors.forename: Magda
authors.initials: M
authors.lastname: Gioia
authors.forename: Hiroki
authors.initials: H
authors.lastname: Tsukada
authors.forename: Jian
authors.initials: J
authors.lastname: Liang
authors.forename: Riccardo
authors.initials: R
authors.lastname: Iundusi
authors.forename: Umberto
authors.initials: U
authors.lastname: Tarantino
authors.forename: Massimo
authors.initials: M
authors.lastname: Coletta
authors.forename: Tayebeh
authors.initials: T
authors.lastname: Pourmotabbed
authors.forename: Stefano
authors.initials: S
authors.lastname: Marini
mesh_terms: D000818:Animals; D055162:Biocatalysis; D024042:Collagen Type I / Q000737:chemistry / Q000378:metabolism*; D007700:Kinetics; D020781:Matrix Metalloproteinase 1 / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism*; D008958:Models, Molecular; D011487:Protein Conformation; D051381:Rats; D011994:Recombinant Proteins / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism*; D013379:Substrate Specificity; D013816:Thermodynamics
chemical_list: D024042:Collagen Type I; D011994:Recombinant Proteins; D020781:Matrix Metalloproteinase 1