title: Inhibition of MMP-2 gelatinolysis by targeting exodomain-substrate interactions.
abstract: MMP-2 (matrix metalloproteinase 2) contains a CBD (collagen-binding domain), which is essential for positioning gelatin substrate molecules relative to the catalytic site for cleavage. Deletion of the CBD or disruption of CBD-mediated gelatin binding inhibits gelatinolysis by MMP-2. To identify CBD-binding sites on type I collagen and collagen peptides with the capacity to compete CBD binding of gelatin and thereby inhibit gelatinolysis by MMP-2, we screened a one-bead one-peptide combinatorial peptide library with recombinant CBD as bait. Analyses of sequences from the CBD-binding peptides pointed to residues 715-721 in human alpha1(I) collagen chain as a binding site for CBD. A peptide (P713) including this collagen segment was synthesized for analyses. In SPR (surface plasmon resonance) assays, the CBD and MMP-2(E404A), a catalytically inactive MMP-2 mutant, both bound immobilized P713 in a concentration-dependent manner, but not a scrambled control peptide. Furthermore, P713 competed gelatin binding by the CBD and MMP-2(E404A). In control assays, neither of the non-collagen binding alkylated CBD or MMP-2 with deletion of CBD (MMP-2DeltaCBD) bound P713. Consistent with the exodomain functions of the CBD, P713 inhibited approximately 90% of the MMP-2 gelatin cleavage, but less than 20% of the MMP-2 activity on a peptide substrate (NFF-1) which does not require the CBD for cleavage. Confirming the specificity of the inhibition, P713 did not alter MMP-2DeltaCBD or MMP-8 activities. These experiments identified a CBD-binding site on type I collagen and demonstrated that a corresponding synthetic peptide can inhibit hydrolysis of type I and IV collagens by competing CBD-mediated gelatin binding to MMP-2.
authors.affiliation: Department of Periodontics, The University of Texas Health Science Center at San Antonio, 7703 Floyd Curl Drive, MC 7894, San Antonio, TX 78229-3900, USA.
authors.forename: Xiaoping
authors.initials: X
authors.lastname: Xu
authors.forename: Zhihua
authors.initials: Z
authors.lastname: Chen
authors.forename: Yao
authors.initials: Y
authors.lastname: Wang
authors.forename: Lynda
authors.initials: L
authors.lastname: Bonewald
authors.forename: Bjorn
authors.initials: B
authors.lastname: Steffensen
mesh_terms: D000595:Amino Acid Sequence; D001667:Binding, Competitive / Q000187:drug effects; D024042:Collagen Type I / Q000378:metabolism; D024141:Collagen Type IV / Q000378:metabolism; D005780:Gelatin / Q000378:metabolism*; D006801:Humans; D020778:Matrix Metalloproteinase 2 / Q000737:chemistry*; D020784:Matrix Metalloproteinase 8 / Q000378:metabolism; D061965:Matrix Metalloproteinase Inhibitors; D008969:Molecular Sequence Data; D050505:Mutant Proteins / Q000378:metabolism; D010455:Peptides / Q000494:pharmacology*; D011485:Protein Binding / Q000187:drug effects; D017434:Protein Structure, Tertiary; D013379:Substrate Specificity / Q000187:drug effects
chemical_list: D024042:Collagen Type I; D024141:Collagen Type IV; D061965:Matrix Metalloproteinase Inhibitors; D050505:Mutant Proteins; D010455:Peptides; D005780:Gelatin; D020778:Matrix Metalloproteinase 2; D020784:Matrix Metalloproteinase 8