Figure 4.
Fig. 4. Heparin binding site. A-C have the dimeric
assemblage oriented as viewed from above Fig. 3A; B-D use the
same color codes as in Fig. 3. (A) Electrostatic potential
surface. Potential is graded from red ( ) to deep
blue (>+16 kT). (B) Sulfate sites superimposed on the molecular
surface. Sulfate ions in the surface channel of the complex are
shown in yellow and sulfonate ions transformed from the
FGF1:heparin structure (8) are in orange. (C) Heparin model
(yellow) superimposed onto worm diagram. Six hexoses at each end
are transformed directly from Ref. 8, and four in the middle are
model built. Side chains of basic residues 176, 178, 208, and
210 are in purple. (D) End view of heparin superimposed onto
worm. The view is rotated by 20°
from Fig. 3A. Drawings were made by GRASP (37).
) to deep
blue (>+16 kT). (B) Sulfate sites superimposed on the molecular
surface. Sulfate ions in the surface channel of the complex are
shown in yellow and sulfonate ions transformed from the
FGF1:heparin structure (8) are in orange. (C) Heparin model
(yellow) superimposed onto worm diagram. Six hexoses at each end
are transformed directly from Ref. 8, and four in the middle are
model built. Side chains of basic residues 176, 178, 208, and
210 are in purple. (D) End view of heparin superimposed onto
worm. The view is rotated by