The isolation and purification of two anionic endothelial cell growth factors from human brain

Two anionic polypeptides which stimulate the proliferation of human umbilical vein endothelial cells have been isolated and purified to homogeneity from human brain using heparin affinity chromatography. The molecular weights of the polypeptides are 18,500 and 19,300; the isoelectric point for both polypeptides is at pH 5.2. The purified polypeptides differed in their ability to stimulate human endothelial cell growth. The half maximal activities observed for the 18.5 and 19.3 kilodalton polypeptides were at concentrations of 10.0 ng/ml and 0.9 ng/ml respectively.