EDTA increases the susceptibility of reelin to uPA and plasmin. Recombinant reelin was incubated with proteases for 6 hrs. and immunoblotted. 1 reelin standard, 2 treated with uPA, 3 treated with uPA in the presence of 10 mM EDTA. 4 reelin standard, 5–6 treated with plasmin (0.5 unit/ml) for 1 and 6 h, 7 treated with plasmin 6 h in the presence of 10 mM EDTA. Incubation for 6 h in the presence of EDTA alone caused no breakdown (not shown).