Vascular endothelial growth factor (VEGF) is the best characterized multifunctional protein which plays a key role in normal and pathologic angiogenesis. The gene encoding the human VEGF(165) was cloned from the ovarian carcinoma cell line (OVCAR3) and expressed in insect cells using the baculovirus expression vector system. The recombinant human VEGF(165) (rhVEGF(165)) protein produced by Sf21 (Spodoptera frugiperda) cells underwent a similar processing compared with mammalian cells, including efficient glycosylation, formation of a disulfide-linked dimer and secretion into the media. The rhVEGF(165) had a high affinity for heparin and this characteristic was used to purify this form to homogeneity by heparin affinity, Resource S and Resource RPC columns. The biological activity of the purified 42-kDa homodimer was shown by the induction of the proliferation of human umbilical vein derived endothelial cells. These results demonstrate that an angiogenic growth factor whose normal processing requires glycosylation and disulfide-bridge formation can be efficiently expressed in high concentration (up to 20 mg/L) in Sf21 cells. (c) 2005 Elsevier Inc. All rights reserved.