Keratin sulfate is a heparin-related proteoglycan that interacts with the receptor or alters its stability and function. Keratin sulfate does not enhance the mitogenic effect of FGF-2[1].
References
[1] M A Caldwell , et al. Heparin, but not other proteoglycans potentiates the mitogenic effects of FGF-2 on mesencephalic precursor cells. Exp Neurol. 1998 Jul;152(1):1-10. DOI:10.1006/exnr.1998.6815
