Generation of a novel proteolysis resistant vascular endothelial growth factor165 variant by a site-directed mutation at the plasmin sensitive cleavage site.

Vascular endothelial growth factor (VEGF) is a potent angiogenic mediator in tissue repair. In non-healing human wounds plasmin cleaves and inactivates VEGF165. In the present study, we generated recombinant VEGF165 mutants resistant to plasmin proteolysis. Substitution of Arg110 with Ala110 or Gln110, and Ala111 with Pro111 yielded plasmin-resistant and biologically active VEGF165 mutants. In addition, substitution of Ala111 with Pro111 resulted in a substantial degree of stabilization when incubated in wound fluid obtained from non-healing wounds. These results suggest that the plasmin cleavage site Arg110/Ala111 and the carboxyl-terminal domain play an important role in the mitogenic activity of VEGF165.