Binding of purified integrin α2β1 to immobilized decorin.
(A) Increasing amounts of purified integrin α2β1 (0, 0.5, 1, 1.5, 2 μg) were added to decorin-coated wells of a microtiter plate in the presence of 2 mM MgCl2. As a negative control, the same amount of purified integrin α2β1 was incubated with BSA-coated wells. Upon incubation for 2 hours, bound integrin α2β1 was revealed by a colorimetric reaction after incubation with an antibody against the α2subunit of integrin α2β1 (1936) and a peroxidase-conjugated antimouse antibody. Data are reported as absorbance at 490 nm of the wells coated with decorin upon subtraction of the values measured in corresponding wells coated with BSA and represent the mean ± SD of 3 separate experiments. (B) Purified integrin α2β1 (1 μg) was added to decorin-coated wells in the presence of 2 mM MgCl2, 2 mM EDTA, 1 μL P1E6 (ascitic fluid), or 1 μg/mL anti-integrin α2β1 monoclonal antibody 1998. Upon incubation for 2 hours, bound integrin α2β1was revealed as described for Figure 8A. Results are the mean ± SD of 3 separate experiments.
