Figure 6.

The interaction site of LRP1 clusters II and IV on C1q is located on the collagen stalks at or close to the site interacting with C1r2s2 tetramer. C1q (10 nM, blue curves), CLR (10 nM, red curves) and GR (60 nM, green curves) were injected over immobilized LRP1 cluster II (1,230 RU, A panel) or LRP1 cluster IV (1,270 RU, B panel), in 50 mM Tris, 150 mM NaCl, 2 mM CaCl₂, 0.05% P20, pH 7.4. C1q (1 nM) was injected on the same amount of clusters II and IV (bottom C, D) with (pink curves) or without (blue curves) C1r2s2 (1 nM). r2s2 was also injected alone (1 nM) as a reference (black curves).