Figure 3. PP13 differentially binds to erythrocytes of distinct ABO blood groups in vivo.
Erythrocyte-binding assay was run with recombinant PP13, truncated PP13 (TrPP13), bovine serum albumin (BSA) and buffer (PBS), and quantified with flow-cytometry. A) PP13-binding to RBCs was specific and mediated by its CRD, as trPP13 bound negligibly to RBCs, similar to BSA. B) PP13 bound to blood-group AB RBCs with the strongest affinity and to blood-group B RBCs with the weakest affinity (data presented for 50 ug/ml PP13 concentration). C) PP13-binding to RBCs of different ABO blood groups dynamically changed according to the applied PP13 concentrations, similar to that observed for other galectins [37], [38]. Mean values of mean fluorescence intensities (±SEM) are presented from five independent experiments that were run in triplicate.