Ligand multimerization effects on binding efficiency of Protein L affinity chromatography resins

Nearly four decades have passed since the discovery of protein-L. Its exceptional ability in binding to the kappa light chain of immunoglobulins makes it a suitable candidate for the purification of certain biotherapeutics, particularly antibody fragments. Efforts have focused on improving its recovery and dynamic binding capacity. Among various strategies, ligand multimerization has shown significant potential in developing more efficient and cost-effective resins. This study employed a multimerization approach to create new recombinant protein-L-based ligands and compare their performance to the commercially available alternatives. Dynamic binding capacity studies revealed that the engineered ProL6 and ProL8 resins exhibited higher binding capacities than the ProL4 and the commercial Capto-L resin. Furthermore, the recovery rates of Fab antibody fragments from bacterial lysates using ProL6, ProL8, and the commercial resin were 92.8, 94.4, and 94.6 %, respectively, comparable to those of the ProL4 resin. SDS-PAGE analysis confirmed the purity of the proteins eluted from all tested resins, aligned with the results of ProL4 resin. Additionally, it evaluated the 100 % specificity of ProL6, ProL8, and the commercial resins.