FIGURE 3.
SPR studies for CTX A2 and A4 binding to immobilized heparin with sulfate specificity. A, effect of distinct sulfation groups on the binding of heparin mimetics to CTX A2 (open symbols) and CTX A4 (close symbols) as revealed by the SPR binding sensograms in the presence of the related desulfated heparin mimetics. The arrows emphasized the difference in Ki values for de-6-O-sulfated heparin binding to CTX A2 and A4. B, the retained CTX were dissociated from immobilized heparin surfaces by injecting heparin through competition. Insert, indicates that the competition of injected heparin was concentration-dependent, reflecting the competitive ability of injected heparin. C, effects of heparin modifications on their competitive abilities as revealed by the dissociation of the retained CTX in the presence of indicated heparin mimetics. de2OS, de-2-O-sulfation; de6OS, de-6-O-sulfation; deNS, de-N-sulfation.