Characterization of angiostatin preparations used in this study. (A) Ten micrograms of rmAst, rhAst, and ehAst were run under reducing conditions in a 9% polyacrylamide gel and stained with Coomassie blue. M_r = relative molecular mass × 1,000. (B) hPlg and rhAst were analyzed by Western blotting under nonreducing conditions using mouse MoAbs 36E6 and 42B12 directed against kringles 1-3/LBSI and kringle 5, respectively.M_r = relative molecular mass × 1,000. (C) Elution profile of rmAst after purification by HPLC.