Praesto Jetted A50 HipH, a mild pH elution protein A resin, exhibits improved aggregate separation capability and protein elution from it shows unique response to mobile phase additive sodium chloride

Protein A affinity chromatography has been widely used for product capture in monoclonal antibody (mAb), bispecific antibody (bsAb) and Fc-fusion protein purification. However, the low pH (i.e., 3.0–3.5) required for elution may cause aggregation and/or truncation for pH-sensitive molecules. Praesto Jetted A50 HipH from Purolite is a newly launched Protein A resin whose ligand is engineered to enable antibody/Fc-fusion elution at a milder pH (i.e., 4.6 or above) and therefore is more suitable to pH-sensitive molecules. In the current study, we demonstrated that this new Protein A resin, besides allowing mild elution, also possesses improved aggregate separation capability in comparison to traditional Protein A resins. While traditional Protein A resins generally lack any aggregate separation capability, Jetted A50 HipH can remove up to 70% of the aggregates in the load while maintaining good monomer recovery. In addition, we discovered that protein elution from Jetted A50 HipH column responded to mobile phase additive sodium chloride differently from that from traditional Protein A columns (elution was promoted rather than suppressed). This property enables elution at further increased pH (i.e., 5) when proper amount of sodium chloride is included in the elution buffer. Thus, Jetted A50 HipH is a better choice than traditional Protein A resins for pH-sensitive and/or aggregation-prone mAbs, bsAbs and Fc-fusion proteins.