Comparison of human and bovine brain derived heparin-binding growth factors.

Two growth factors have been purified to homogeneity from human brain using heparin affinity chromatography. They have apparent molecular weights of 17 Kd and 18 Kd. Their amino acid compositions differ, but are similar to those of the two heparin-binding growth factors present in bovine neural tissue. These results suggest that the heparin-binding growth factors in neural tissue can be grouped into two distinct classes.