Single and binary adsorption of proteins on ion‐exchange adsorbent: The effectiveness of isothermal models

Abstract

Simultaneous and sequential adsorption equilibria of single and binary adsorption of bovine serum albumin and bovine hemoglobin on Q Sepharose FF were investigated in different buffer constituents and initial conditions. The results in simultaneous adsorption showed that both proteins underwent competitive adsorption onto the adsorbent following greatly by protein-surface interaction. Preferentially adsorbed albumin complied with the universal rule of ion-exchange adsorption whereas buffer had no marked influence on hemoglobin adsorption. Moreover, an increase in initial ratios of proteins was benefit to a growth of adsorption density. In sequential adsorption, hemoglobin had the same adsorption densities as single-component adsorption. It was attributed to the displacement of preadsorbed albumin and multiple layer adsorption of hemoglobin. Three isothermal models (i.e. extended Langmuir, steric mass-action, and statistical thermodynamic (ST) models) were introduced to describe the ion-exchange adsorption of albumin and hemoglobin mixtures. The results suggested that extended Langmuir model gave the lowest deviation in describing preferential adsorption of albumin at a given salt concentration while steric mass-action model could very well describe the salt effect in albumin adsorption. For weaker adsorbed hemoglobin, ST model was the preferred choice. In concert with breakthrough data, the research further revealed the complexity in ion-exchange adsorption of proteins.

Extended Elution by Characteristic Point Method for Characterization of Protein Ion‐Exchange Adsorption

“…Here, the experimental results correspond well with the work of Yu et al . The results of Liang et al are in the same order of magnitude. Both authors use the Langmuir model for the mathematical description of their results, given by: …”

“…Due to similar physical properties, with the exception of the isoelectric point (pI), bovine hemoglobin (bHb) is selected as a marker substance. While BSA has a pI of 4.9, bHb has a pI of 7.0-7.4 [17]. Therefore, no or nearly no adsorption of bHb is expected under the investigated condition.…”

Molecular Dynamics Simulations of a Binary Protein Mixture Adsorption onto Ion-Exchange Adsorbent

“…In binary adsorption simulations, HSA and bHb adsorbed onto Q Sepharose FF competitively. 2 The adsorption depends mainly on the protein−ligand interaction. In addition, the interactions between the different proteins influence the binary adsorption.…”

Enrichment of total steroidal saponins from the extracts ofTrillium tschonoskiiMaxim by macroporous resin and the simultaneous determination of eight steroidal saponins in the final product by HPLC

“…Conventionally, methods for the preparative enrichment of active ingredients from plant extracts include LLE , precipitation , membrane filtration , ion exchange , and expanded bed adsorption . However, there are many shortcomings to these methods, such as their environmental contamination, high costs, time‐consuming nature, and small adsorption amounts.…”