title: Catalytic activities and substrate specificity of the human membrane type 4 matrix metalloproteinase catalytic domain.
abstract: Membrane type (MT) matrix metalloproteinases (MMPs) are recently recognized members of the family of Zn(2+)- and Ca(2+)-dependent MMPs. To investigate the proteolytic capabilities of human MT4-MMP (i.e. MMP-17), we have cloned DNA encoding its catalytic domain (CD) from a breast carcinoma cDNA library. Human membrane type 4 MMP CD (MT4-MMPCD) protein, expressed as inclusion bodies in Escherichia coli, was purified to homogeneity and refolded in the presence of Zn(2+) and Ca(2+). While MT4-MMPCD cleaved synthetic MMP substrates Ac-PLG-[2-mercapto-4-methylpentanoyl]-LG-OEt and Mca-PLGL-Dpa-AR-NH(2) with modest efficiency, it catalyzed with much higher efficiency the hydrolysis of a pro-tumor necrosis factor-alpha converting enzyme synthetic substrate, Mca-PLAQAV-Dpa-RSSSR-NH(2). Catalytic efficiency with the pro-tumor necrosis factor-alpha converting enzyme substrate was maximal at pH 7.4 and was modulated by three ionizable enzyme groups (pK(a3) = 6.2, pK(a2) = 8.3, and pK(a1) = 10.6). MT4-MMPCD cleaved gelatin but was inactive toward type I collagen, type IV collagen, fibronectin, and laminin. Like all known MT-MMPs, MT4-MMPCD was also able to activate 72-kDa progelatinase A to its 68-kDa form. EDTA, 1,10-phenanthroline, reference hydroxamic acid MMP inhibitors, tissue inhibitor of metalloproteinases-1, and tissue inhibitor of metalloproteinases-2 all potently blocked MT4-MMPCD enzymatic activity. MT4-MMP is, therefore, a competent Zn(2+)-dependent MMP with unique specificity among synthetic substrates and the capability to both degrade gelatin and activate progelatinase A.
authors.affiliation: Department of Biochemistry, Parke-Davis Pharmaceutical Research Division, Warner-Lambert Company, Ann Arbor, Michigan 48105, USA.
authors.forename: Y
authors.initials: Y
authors.lastname: Wang
authors.forename: A R
authors.initials: AR
authors.lastname: Johnson
authors.forename: Q Z
authors.initials: QZ
authors.lastname: Ye
authors.forename: R D
authors.initials: RD
authors.lastname: Dyer
mesh_terms: D000595:Amino Acid Sequence; D001665:Binding Sites; D002614:Chelating Agents / Q000494:pharmacology; D003001:Cloning, Molecular; D004789:Enzyme Activation; D004791:Enzyme Inhibitors / Q000494:pharmacology; D004792:Enzyme Precursors / Q000378:metabolism; D004926:Escherichia coli; D005780:Gelatin / Q000378:metabolism; D018093:Gelatinases / Q000378:metabolism; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D020782:Matrix Metalloproteinases / Q000737:chemistry / Q000235:genetics*; D053504:Matrix Metalloproteinases, Membrane-Associated; D008666:Metalloendopeptidases / Q000378:metabolism; D008969:Molecular Sequence Data; D017510:Protein Folding; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics; D013379:Substrate Specificity; D015032:Zinc / Q000737:chemistry
chemical_list: D002614:Chelating Agents; D004791:Enzyme Inhibitors; D004792:Enzyme Precursors; D011994:Recombinant Proteins; D005780:Gelatin; D018093:Gelatinases; C402225:MMP17 protein, human; D020782:Matrix Metalloproteinases; D053504:Matrix Metalloproteinases, Membrane-Associated; D008666:Metalloendopeptidases; C069860:progelatinase; D015032:Zinc