Inhibition of binding of basic fibroblast growth factor to low and high affinity receptors by carrageenans.
The effect of carrageenans, a family of polysulphated polysaccharides, on the binding of basic fibroblast growth factor (bFGF) to low affinity (heparin-like) receptors and high affinity receptors on baby hamster kidney cells was investigated. kappa-, iota-, and lambda-carrageenans all inhibited binding of bFGF to both types of receptors with iota-carrageenan being the most potent inhibitor (IC50 values of approx. 0.7 and 4 micrograms/mL for inhibition of binding to low and high affinity receptors respectively). Heparin reduced the inhibition of bFGF binding to high affinity receptors caused by iota-carrageenan. Heparin and iota-carrageenan were comparable in their activities at displacing pre-bound bFGF from both low affinity receptors and high affinity receptors. These results indicate that iota-carrageenan binds to the heparin-binding domain on bFGF and that this may be sufficient to reduce the ability of bFGF to bind to high affinity receptors.
Hoffman
R
R
Clinical Oncology and Radiotherapeutics Unit, MRC Centre, Cambridge, U.K.
Sykes
D
D
D000818:Animals; D001665:Binding Sites / Q000187:drug effects; D001667:Binding, Competitive; D002351:Carrageenan / Q000494:pharmacology*; D002460:Cell Line; D006224:Cricetinae; D004305:Dose-Response Relationship, Drug; D016222:Fibroblast Growth Factor 2 / Q000187:drug effects / Q000378:metabolism*; D006493:Heparin / Q000494:pharmacology; D011485:Protein Binding / Q000187:drug effects; D017468:Receptors, Fibroblast Growth Factor / Q000378:metabolism*
D017468:Receptors, Fibroblast Growth Factor; D016222:Fibroblast Growth Factor 2; D002351:Carrageenan; D006493:Heparin