Activation of progelatinase B (proMMP-9) by active collagenase-3 (MMP-13).
Human progelatinase B was activated by collagenase-3 in a time-dependent fashion. Activation proceeded through an intermediate form of Mr 86,000 to the final active form of Mr 82,000. N-terminal amino acid sequence determination demonstrated that the Glu40-Met41 peptide bond was initially hydrolysed followed by cleavage of the Arg87-Phe88 peptide bond releasing the rest of the propeptide domain which was accompanied by the achievement of maximal enzymatic activity as revealed using a quenched fluorescent substrate. Kinetic analysis of activation revealed that the rates were dependent on the concentration of the proenzyme as well as active collagenase-3. Active gelatinase B did not contribute to the activation rate of the proenzyme initiated by collagenase-3 and our results indicate that progelatinase B activation proceeds via bimolecular cleavage with collagenase-3 involving sequential cleavage of the propeptide in two steps. The activation rates were not dependent on C-terminal domain interactions between progelatinase B and collagenase-3, as assessed using wild-type and C-terminal deletion mutants of both enzymes. Since elevated levels of both gelatinase B and collagenase-3 have been observed in arthritis and breast cancer pathology these enzymes may well form a proteolytic cascade in these diseases which allows rapid turnover of the extracellular matrix.
Knäuper
V
V
Department of Cell and Molecular Biology, Strangeways Research Laboratory, Cambridge, UK.
Smith
B
B
López-Otin
C
C
Murphy
G
G
D000595:Amino Acid Sequence; D001665:Binding Sites; D017364:Collagenases / Q000737:chemistry / Q000378:metabolism*; D004789:Enzyme Activation; D004792:Enzyme Precursors / Q000737:chemistry / Q000378:metabolism*; D018093:Gelatinases / Q000737:chemistry / Q000378:metabolism*; D007700:Kinetics; D053509:Matrix Metalloproteinase 13; D008666:Metalloendopeptidases / Q000737:chemistry / Q000378:metabolism*; D008969:Molecular Sequence Data; D011499:Protein Processing, Post-Translational
D004792:Enzyme Precursors; D017364:Collagenases; D018093:Gelatinases; C507079:MMP13 protein, human; D053509:Matrix Metalloproteinase 13; D008666:Metalloendopeptidases; C069860:progelatinase