For the monovalent psDiMan binding study, the psDiMan was dissolved in the binding buffer to obtain a final concentration of 50 mM. DC-SIGN was concentrated by centrifugal ultrafiltration (10 kDa MWCO filter), to obtain a final concentration of 15 µM. Isothermal titration calorimetry was performed using a MicroCal iTC200, with the psDiMan solution loaded into the syringe, and DC-SIGN loaded into the calorimeter cell. Titrations were conducted at 25 °C with an initial 0.5 L injection, followed by nineteen 2 L injections.