title: Activity of matrix metalloproteinase-9 against native collagen types I and III.
abstract: Interstitial collagen types I, II and III are highly resistant to proteolytic attack, due to their triple helical structure, but can be cleaved by matrix metalloproteinase (MMP) collagenases at a specific site, approximately three-quarters of the length from the N-terminus of each chain. MMP-2 and -9 are closely related at the structural level, but MMP-2, and not MMP-9, has been previously described as a collagenase. This report investigates the ability of purified recombinant human MMP-9 produced in insect cells to degrade native collagen types I and III. Purified MMP-9 was able to cleave the soluble, monomeric forms of native collagen types I and III at 37 degrees C and 25 degrees C, respectively. Activity against collagens I and III was abolished by metalloproteinase inhibitors and was not present in the concentrated crude medium of mock-transfected cells, demonstrating that it was MMP-9-derived. Mutated, collagenase-resistant type I collagen was not digested by MMP-9, indicating that the three-quarters/one-quarter locus was the site of initial attack. Digestion of type III collagen generated a three-quarter fragment, as shown by comparison with MMP-1-mediated cleavage. These data demonstrate that MMP-9, like MMP-2, is able to cleave collagens I and III in their native form and in a manner that is characteristic of the unique collagenolytic activity of MMP collagenases.
authors.affiliation: Musculoskeletal Research Group, Institute of Cellular Medicine, The Medical School, Framlington Place, Newcastle University, Newcastle-upon-Tyne, UK.
authors.forename: Heather F
authors.initials: HF
authors.lastname: Bigg
authors.forename: Andrew D
authors.initials: AD
authors.lastname: Rowan
authors.forename: Michael D
authors.initials: MD
authors.lastname: Barker
authors.forename: Tim E
authors.initials: TE
authors.lastname: Cawston
mesh_terms: D000818:Animals; D024042:Collagen Type I / Q000737:chemistry / Q000378:metabolism*; D024061:Collagen Type III / Q000737:chemistry / Q000378:metabolism*; D017077:Culture Media, Conditioned / Q000737:chemistry; D018076:DNA, Complementary; D004926:Escherichia coli / Q000235:genetics; D006801:Humans; D020780:Matrix Metalloproteinase 9 / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D008970:Molecular Weight; D011994:Recombinant Proteins / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism; D012995:Solubility; D018411:Spodoptera / Q000166:cytology / Q000378:metabolism; D013696:Temperature
chemical_list: D024042:Collagen Type I; D024061:Collagen Type III; D017077:Culture Media, Conditioned; D018076:DNA, Complementary; D011994:Recombinant Proteins; D020780:Matrix Metalloproteinase 9