Production and characterization of the extracellular domain of recombinanthuman fibroblast growth factor receptor 4

Among the members of the fibroblast growth factor receptor family the FGFR4 has demonstrated strong dependence on heparin-like material for its activa tion by fibroblast growth factors. We have produced and characterized a rec ombinant human FGFR4 extracellular domain (FCFR4ed), in order to study its biochemical properties in isolated conditions. The FGFR4ed was expressed in an insect cell system and purified from the culture medium by Ni2+-affinit y and gel filtration chromatography. Pure FGFR4ed was tested for FOF- and h eparin-binding by covalent crosslinking experiments and by biosensor analys is. In solution, FGFR4ed formed complexes with acidic FGF (FGF-1) and basic FGF (FGF-2), both in the presence and absence of heparin. Immobilized FGFR 4 also bound FGF-8 besides FGF-1 and FGF-2. Furthermore, heparin alone indu ced receptor oligomerization on the surface of the receptor coupled chip. T hus, the recombinant FGFR4ed revealed properties described for the cellular form of this receptor and can be used for interaction studies. (C) 2000 El sevier Science Ltd. All rights reserved.