Biochemical characterization of the molecular interaction between recombinant basic fibroblast growth factor and a recombinant soluble fibroblast growth factor receptor.
The extracellular domain of human fibroblast growth factor receptor (XC-FGF-R) was expressed in Escherichia coli. The protein was purified to homogeneity and the interaction with basic fibroblast growth factor (bFGF), its physiological ligand, was examined. Using resins on which bFGF was reversibly bound, we analysed the characteristics of the binding between XC-FGF-R and immobilized bFGF. We also investigated the stoichiometry of the binding between XC-FGF-R and recombinant human bFGF (rhbFGF) applying non-denaturing gel electrophoresis, chemical cross-linking followed by SDS/PAGE, and gel-filtration chromatography. In cross-linking and gel-filtration chromatography experiments, a 1:1 complex between rhbFGF and XC-FGF-R was observed. The complex was separated from the non-complexed proteins using non-denaturing PAGE in the presence of 0.1% Triton X-100. The band corresponding to the complex was recognized by specific antibodies directed against bFGF and its receptor, blotted on poly(vinylidene difluoride) membranes and submitted to sequence and amino acid analysis. The data obtained from these determinations confirmed the formation of a 1:1 complex between rhbFGF and XC-FGF-R.
Department of Biotechnology, Farmitalia Carlo Erba, Nerviano, Italy.
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Caccia
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Cletini
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A
Isacchi
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L
Bergonzoni
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G
Orsini
D016222:Fibroblast Growth Factor 2 / Q000378:metabolism*; D066298:In Vitro Techniques; D011485:Protein Binding; D017468:Receptors, Fibroblast Growth Factor / Q000378:metabolism*; D011994:Recombinant Proteins; D012995:Solubility
D017468:Receptors, Fibroblast Growth Factor; D011994:Recombinant Proteins; D016222:Fibroblast Growth Factor 2