The present invention involves the preparation of vascular endothelial
growth factor (VEGF) variants which provide materials that are selective
in respect of binding characteristics to the kinase domain region and the
FMS-like tyrosine-kinase region, respectively KDR and FLT-1. The
respective KDR and FLT-1 receptors are bound by corresponding domains
within the VEGF compound domains. The variants hereof define those two
binding regions and modify them so as to introduce changes that interrupt
the binding to the respective domain. In this fashion the final
biological characteristics of the VEGF molecule are selectively modified.