Figure 3.

Collagen type XI restrains integrin-binding site availability on collagen type I. (A) Collagen type XI inhibits C2C12-α11 binding on fibrillar collagen type I. C2C12 cells expressing either integrin α2 (C2C12-α2) or integrin α11 (C2C12-α11) were seeded on monomeric or fibrillar collagen type I, collagen type XI or a mix of both collagens at a ratio of 3:1 for 40 min. Cells were stained with crystal violet and absorbance was read at 595 nm. Statistics were performed using Mann–Whitney test (mean ± SD). Dose-effect of collagen type XI on inhibition of cell attachment to collagen type I has been analyzed on fibrillar (B) and monomeric (C) collagens. C2C12-α11 cells were seeded on collagen type I, collagen type XI or a mix of both collagens at different ratios (total collagen concentration is constant) for 40 min. Cells were stained with crystal violet and absorbance was read at 595 nm. Statistics were performed using Mann–Whitney test (*, p = 0.00433; **, p = 0.00216; ***, p = 0.00499, mean ± SD). (D) Determination of the half-maximal inhibitory concentration (IC₅₀) of collagen type XI to inhibit cell binding to fibrillar collagen type I. IC₅₀ has been calculated based on the results presented in the (B).