Here, the apparent-𝐾 i values for DC-SIGN and DC-SIGNR were estimated as 8.0 ± 0.1 and 4.2 ± 0.2 mM, respectively. The higher 𝐾 i value for DC-SIGN is a reflection of its stronger overall binding affinity with QR-DiMan, and hence requires a higher [Man] in order to displace 50% of binding interactions. However, DC-SIGNR displays a broader decay with increasing [Man] than DC-SIGN does, evidenced by the smaller exponent (𝑛 = 1.78 ± 0.05 vs 1.21 ± 0.08 for DC-SIGN vs DC-SIGNR). This suggests that Man is able to displace a larger amount of DC-SIGNR binding at much lower Cs than DC-SIGN. It is worth noting that, where the difference in the overall apparent-𝐾 d between DC-SIGN/R binding to QR-DiMan is ~100-fold, the difference in the apparent-𝐾 i with Man is only ~2 fold. This may suggest that, for a PQR of 4:1, the simultaneous binding mode of DC-SIGNR provides a higher contribution to the apparent-𝐾 i than the crosslinking mode, where the latter contributes mainly to broadening of the decay. Interestingly, because the fluorescent core of the QR has been shown to be located in the center of the cylindrical middle section of the QR, any binding at the middle section will have a larger influence on the apparent-𝐾 i . This result may therefore suggest that the glycan display at the cylindrical section of the rod is better suited to form simultaneous binding with DC-SIGNR than crosslinking interactions. Consistent with this, the decay in 𝐷 h for the simultaneously bound complexes also occurs at the same [Man] range (Figure ).