Premium
Single and binary adsorption of proteins on ion‐exchange adsorbent: The effectiveness of isothermal models
Author(s) -
Liang Juan,
Fieg Georg,
Shi QingHong,
Sun Yan
Publication year - 2012
Publication title -
journal of separation science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.72
H-Index - 102
eISSN - 1615-9314
pISSN - 1615-9306
DOI - 10.1002/jssc.201200101
Subject(s) - adsorption , chemistry , steric effects , chromatography , hemoglobin , isothermal process , bovine serum albumin , ion exchange , protein adsorption , isothermal titration calorimetry , langmuir , langmuir adsorption model , albumin , inorganic chemistry , ion , organic chemistry , thermodynamics , biochemistry , physics
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.