Effect of solution condition on the binding behaviors of monoclonal antibody and fusion protein therapeutics in Protein A chromatography

•Fc-based proteins showed pH-dependent Protein A binding behaviors in basic solution conditions.•The binding capacity decreased by ∼30% from pH 9 to 10 on two Protein A resins.•The mAbs had higher binding capacity but weaker binding affinity than the Fc-fusion protein.•The surface diffusivity coefficient was inversely correlated with the binding affinity.•Post-load chase profiles facilitated model analysis and practical binding capacity measurements.