IDENTIFICATION OF A HEPARIN-BINDING GROWTH-FACTOR AND OF ITS AFFINITY BINDING-SITES IN THE MARINE ANNELID NEREIS-DIVERSICOLOR

1. Fractionation of "tracts of the marine annelid Nereis diversicolor by heparin-Sepharose affinity chromatography yielded a peak of mitogenic activity for vertebrate fibroblasts. 2. After further purification, the peptide (M(r) 19,000) was recognized by antibodies to bovine aFGF or bFGF and was designated nHBGF (for nereid heparin-binding growth factor). 3. Scatchard analysis, using bovine [I-125]-basic FGF on membrane preparation of Nereis, showed that the tissues of this animal possessed high- and low-affinity binding sites for this growth factor. 4. This binding is challenged by nHBGF. 5. Thus Nereis appears to be the first reported invertebrate possessing a growth factor and its corresponding receptors related to vertebrate FGFs.