Partial molecular characterization of endothelial cell mitogens from human brain: acidic and basic fibroblast growth factors.

Two endothelial cell growth factors have been isolated from human brain extracts by a procedure involving heparin-Sepharose affinity chromatography and reverse-phase HPLC. On the basis of molecular size, amino acid composition and extended amino-terminal sequences, the two proteins are structurally closely related to bovine acidic and basic fibroblast growth factors (aFGF, bFGF). The N-terminal sequences of human and bovine aFGF differ in two positions while those for bFGF are indistinguishable. Human aFGF is microheterogenous: in addition to aFGF two N-terminally truncated forms lacking the first and the seven first amino acids, respectively, were characterized. Human and bovine mitogens possess similar mitogenic activities.