The 28-kDa N-terminal domain of mouse stromelysin-3 has the general properties of a weak metalloproteinase.
The putative matrix metalloproteinase mouse stromelysin-3 was expressed from Escherichia coli and from a mouse myeloma cell line. In the former case a single major protein of 58-kDa was detectable by immunoblotting, but no proteolytic activity could be elicited by zymography or trypsin or organomercurial treatment as would be expected for a typical matrix metalloproteinase. In the latter case immunodetectable proteins of 55-58 and 27-28-kDa were produced. The effect of trypsin or organomercurial treatment of the 55-58-kDa forms was to generate a 51-kDa form and lower molecular mass fragments. Upon zymographic analysis only the 27-28-kDa forms showed caseinolytic activity. N-terminal sequencing and immunoblotting analysis with antibodies specific to distinct domains of stromelysin-3 indicated that the 27-28-Da stromelysin-3 forms had lost the predicted propeptide and the majority of the C-terminal domain. The purified 28-kDa form of stromelysin-3 could weakly degrade a number of extracellular matrix proteins and was inhibited by TIMP. However, the evidence that mature full-length stromelysin-3 is a metalloproteinase could not be substantiated and the precise role of this protein in vivo remains to be elucidated. By partial analogy with interstitial collagenase, one hypothesis is that stromelysin-3 with an intact C-terminal domain has specific properties for an as yet undefined substrate.
Murphy
G
G
Strangeways Research Laboratory, Cambridge, United Kingdom.
Segain
J P
JP
O'Shea
M
M
Cockett
M
M
Ioannou
C
C
Lefebvre
O
O
Chambon
P
P
Basset
P
P
D000595:Amino Acid Sequence; D000818:Animals; D015153:Blotting, Western; D003001:Cloning, Molecular; D004591:Electrophoresis, Polyacrylamide Gel; D006023:Glycoproteins / Q000494:pharmacology; D006801:Humans; D006868:Hydrolysis; D053507:Matrix Metalloproteinase 11; D008666:Metalloendopeptidases / Q000037:antagonists & inhibitors / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism*; D051379:Mice; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000378:metabolism; D011499:Protein Processing, Post-Translational; D011994:Recombinant Proteins / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism; D013379:Substrate Specificity; D019714:Tissue Inhibitor of Metalloproteinases; D014407:Tumor Cells, Cultured
D006023:Glycoproteins; D010446:Peptide Fragments; D011994:Recombinant Proteins; D019714:Tissue Inhibitor of Metalloproteinases; D053507:Matrix Metalloproteinase 11; D008666:Metalloendopeptidases