Mechanistic analysis on the effects of salt concentration and pH on protein adsorption onto a mixed-mode adsorbent with cation ligand.

Streamline Direct HST is a new kind of mixed-mode adsorbent with cation exchange ligand, especially developed for the expanded bed adsorption process, which can capture target protein directly from the moderate ionic strength feedstock without the need of dilution or other additives. In this study, the isotherm adsorption behaviors and the isocratic retention factors of bovine serum albumin (BSA) on Streamline Direct HST were measured, and the corresponding adsorption mechanisms were also described. The results indicated that Streamline Direct HST shows the typical property of salt-independent adsorption and the maximum binding capacity of BSA occurs near the isoelectric point of BSA. When there are some amounts of electrostatic repulsion protein-adsorbent interactions, the multilayer adsorption could be found, and high salt concentration does not favor the adsorption of protein. A patch-controlled adsorption process and an oriented adsorption model are proposed for describing the adsorption behaviors under electrostatic repulsion condition.

[1]  C. Tanford,et al.  The Reversible Expansion of Bovine Serum Albumin in Acid Solutions1 , 1955 .

[2]  Sven-Olof Enfors,et al.  Recovery of recombinant beta-glucosidase by expanded bed adsorption from Pichia pastoris high-cell-density culture broth. , 2006, Journal of biotechnology.

[3]  Robert K. Scopes,et al.  Protein Purification: Principles and Practice , 1982 .

[4]  R. Martenson.  The use of gel filtration to follow conformational changes in proteins. Conformational flexibility of bovine myelin basic protein. , 1978, The Journal of biological chemistry.

[5]  Bo-Lennart Johansson,et al.  Preparation and characterization of prototypes for multi-modal separation media aimed for capture of negatively charged biomolecules at high salt conditions. , 2003, Journal of chromatography. A.

[6]  A. Rodrigues,et al.  Experimental and modeling study of protein adsorption in expanded bed , 2005 .

[7]  L. McLaughlin.  Mixed-mode chromatography of nucleic acids , 1989 .

[8]  Shan-Jing Yao,et al.  Measurement and Correlation of Protein Adsorption with Mixed-Mode Adsorbents Taking into Account the Influences of Salt Concentration and pH , 2006 .

[9]  D. Harding,et al.  Hydrophobic charge induction chromatography: salt independent protein adsorption and facile elution with aqueous buffers. , 1998, Journal of chromatography. A.

[10]  D C Carter,et al.  Structure of serum albumin. , 1994, Advances in protein chemistry.

[11]  J. Ochoa,et al.  Hydrophobic (interaction) chromatography. , 1978, Biochimie.

[12]  W. Norde,et al.  The adsorption of human plasma albumin and bovine pancreas ribonuclease at negatively charged polystyrene surfaces: I. Adsorption isotherms. Effects of charge, ionic strength, and temperature , 1978 .

[13]  D. Lin,et al.  Protein adsorption kinetics of mixed-mode adsorbent with benzylamine as functional ligand , 2006 .

[14]  F. Regnier,et al.  Multimodal liquid chromatography columns for the separation of proteins in either the anion-exchange or hydrophobic-interaction mode. , 1986, Journal of chromatography.

[15]  F. Regnier,et al.  The role of protein structure in chromatographic behavior. , 1987, Science.

[16]  D. Harding,et al.  Salt-independent adsorption chromatography: new broad-spectrum affinity methods for protein capture. , 2001, Journal of biochemical and biophysical methods.

[17]  D. Harding,et al.  One step purification of chymosin by mixed mode chromatography. , 1997, Biotechnology and bioengineering.

[18]  L. Mei,et al.  Separation of nattokinase fromBacillus subtilis fermentation broth by expanded bed adsorption with mixed-mode adsorbent , 2005 .

[19]  Vera G. Mata,et al.  Expanded bed adsorption/desorption of proteins with Streamline Direct CST I adsorbent , 2006, Biotechnology and bioengineering.

[20]  Marcus Textor,et al.  Bovine serum albumin adsorption onto colloidal Al2O3 particles: a new model based on zeta potential and UV-vis measurements. , 2004, Langmuir : the ACS journal of surfaces and colloids.

[21]  K. Sharp,et al.  Calculating the electrostatic potential of molecules in solution: Method and error assessment , 1988 .

[22]  F Luechau,et al.  Development of a mixed mode adsorption process for the direct product sequestration of an extracellular protease from microbial batch cultures. , 2000, Journal of biotechnology.