FIGURE 9.

Identification of the structural specificity underlying the interactions of five FGFs with heparin. DSF was used to establish the relative affinity of each FGF for a library of modified heparins and heparin fragments of defined sizes. The binding specificity of the FGFs for the polysaccharides is revealed following principal component analysis by a combination of their interactions with heparin fragments and the modified heparin library. The three-dimensional plot (PC1 versus PC2 versus PC3) indicated that FGFs binding is affected by both substitution pattern and size of heparin represented by the first three components. PC1 explains 59.01%, PC2 explains 23.96%, and PC3 explains 10.34% of the variance.