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Figure 1. COMP associates with ADAMTS-7. A) GST pulldown assay. Purified GST or GST7-CT fusion protein immobilized on beads was incubated with purified hCOMP in the presence or absence of 5 mM Ca2+. Proteins trapped were examined by immunoblotting with anti-COMP antibodies. Purified COMP (lane 1) was used as a positive control. B) Solid-phase assay. Various amounts of His-TS7C4TSP were immobilized on solid-phase plates. After being blocked, COMP was added to each well, followed by addition of 10 mM CaCl2. Bound protein from the liquid phase was detected using anti-COMP antibodies. C) CO-IP assay. Cartilage extracts were incubated with either anti-COMP antibodies or control IgG, and immunoprecipitated protein complex and cartilage extracts (serving as a positive control) were examined by Western blotting with an anti-ADAMTS-7 antibody.
