title: Catalytic domain comparisons of human fibroblast-type collagenase, stromelysin-1, and matrilysin.
abstract: The propeptide plus the catalytic domain of human fibroblast-type collagenase, stromelysin-1, and matrilysin were expressed in Escherichia coli to directly compare the properties of all three catalytic domains utilizing the same assays. Truncated fibroblast-type collagenase (mini-CL), truncated stromelysin-1 (mini-SL-1), and matrilysin, like their native counterparts, could be activated by organomercurials, trypsin, or SDS. The mini-CL and mini-SL-1 displayed catalytic properties similar to their native counterparts, except that the mini-CL could not cleave native type I collagen. The k(cat)/Km for matrilysin (355 microM(-1) h(-1)) on the synthetic Mca-peptide was much higher than that for mini-CL (69 microM(-1) h(-1)) or mini-SL-1 (23.6 microM(-1) h(-1)). Mini-SL-1 and matrilysin, but not mini-CL, were capable of superactivating collagenase thus increasing the rate of collagen cleavage. Mini-CL and mini-SL-1, but not matrilysin, were able to form SDS-stable complexes with TIMP-1 when co-incubated with an organomercurial and TIMP-1. The second-order rate constant (k(on)) for TIMP-1 inhibition of mini-CL and mini-SL-1 were similar, 0.635 x 10(5) M(-1) s(-1) and 1.52 x 10(5) M(-1) s(-1), respectively. The k(on) for TIMP-1 inhibition of matrilysin was lower (0.130 x 10(5) M(-1) s(-1)) supporting the observation that no SDS stable complexes were detected. This study demonstrates that these catalytic domains are distinct and play a major role in the specificity of these enzymes in regard to rate of catalysis, TIMP-1 binding, and superactivation of collagenase.
authors.affiliation: Research Center in Oral Biology, University of Alabama at Birmingham, 35294, USA. jwindsor@bmg.bhs.uab.edu
authors.forename: L J
authors.initials: LJ
authors.lastname: Windsor
authors.forename: D L
authors.initials: DL
authors.lastname: Steele
authors.forename: S B
authors.initials: SB
authors.lastname: LeBlanc
authors.forename: K B
authors.initials: KB
authors.lastname: Taylor
mesh_terms: D002384:Catalysis; D017364:Collagenases / Q000096:biosynthesis / Q000737:chemistry*; D004926:Escherichia coli / Q000378:metabolism; D006023:Glycoproteins / Q000494:pharmacology; D006801:Humans; D019278:Matrix Metalloproteinase 3 / Q000096:biosynthesis / Q000737:chemistry*; D020783:Matrix Metalloproteinase 7; D020784:Matrix Metalloproteinase 8; D008666:Metalloendopeptidases / Q000096:biosynthesis / Q000737:chemistry*; D019714:Tissue Inhibitor of Metalloproteinases
chemical_list: D006023:Glycoproteins; D019714:Tissue Inhibitor of Metalloproteinases; D017364:Collagenases; D008666:Metalloendopeptidases; D019278:Matrix Metalloproteinase 3; D020783:Matrix Metalloproteinase 7; D020784:Matrix Metalloproteinase 8