Figure 1.

VEGF-A is cleaved by a subset of MMPs. (A) Biotinylated mVEGF₁₆₄ was incubated with the indicated MMPs. The digestion products were resolved in tricine gels and were detected by avidin-HRP. (right) The presence of heparin was tested to evaluate its effect in VEGF processing by MMP3 and MMP9. (B and C) mVEGF₁₆₄ was incubated with MMP3 at different time points (B) and molar ratios (C) as indicated. VEGF cleavage was visualized by SDS-PAGE followed by silver staining. In these experiments, nonglycosylated mVEGF₁₆₄ was used, hence the smaller size. (D) Both mVEGF₁₆₄ and mVEGF₁₈₈ were incubated with MMP3. VEGF cleavage was examined with immunoblots probed with an amino-terminal antibody (463; see Fig. 3 A). Glycosylated mVEGF₁₆₄ was used for A and D, and nonglycosylated mVEGF₁₆₄ was used for B and C. Note the faster mobility in B and C. 44 kD, glycosylated mVEGF₁₆₄ dimer; 22 kD, glycosylated mVEGF₁₆₄ monomer; 19 kD, nonglycosylated mVEGF₁₆₄ monomer; 16 kD, glycosylated mVEGF₁₆₄-cleaved monomer fragment; 13 kD, nonglycosylated mVEGF₁₆₄-cleaved monomer fragment; 6 kD, mVEGF₁₆₄-cleaved monomer fragment. V, VEGF; M, MMP3; VM, VEGF + MMP3; ADAMTS, a disintegrin and metalloproteinase domain with thrombospondin repeats.