The effects of ligand chain length, salt concentration and temperature on the adsorption of bovine serum albumin onto polypropyleneglycol–Sepharose

Abstract

The interaction thermodynamics associated with bovine serum albumin adsorption on polypropylene glycol (n=3)-Sepharose CL-6B and polypropylene glycol (n=7)-Sepharose CL-6B, using ammonium sulfate as the modulator was studied. Analysis of data under linear conditions was accomplished with the stoichiometric displacement retention model, preferential interaction approach and van't Hoff plots applied to HIC systems. Preferential interaction analysis indicated a strong entropic driving force under linear conditions, due to the release of a large amount of solvent on adsorption. In contrast, flow microcalorimetry under overloaded conditions showed that the adsorption of bovine serum albumin may be entropically or enthalpically driven. It is postulated that adsorption in the nonlinear region is influenced by the degree of water release, protein-protein interactions on the surface, reorientation of ligand, and conformational changes in the protein.

Modified Silver Nanoparticle as a Hydrophobic Affinity Probe for Analysis of Peptides and Proteins in Biological Samples by Using Liquid−Liquid Microextraction Coupled to AP-MALDI-Ion Trap and MALDI-TOF Mass Spectrometry

“…In general, an analyte with a longer alkyl chain results in a longer retention time because it increases the molecule's hydrophobicity. [26][27][28] The thermodynamic studies are also described for the hydrophobic interaction of polypeptide with nonpolar ligands. 29,30 However, Orlando et al demonstrated the hydrophobic interaction between the self-assembled monolayer of octadecyl mercaptan and octadecanethiol (C 18 ) with polypeptide in the isolation and concentration of analytes for MALDI-MS analysis.…”

Microcalorimetric Analysis of the Adsorption of Lysozyme and Cytochrome c onto Cation-Exchange Chromatography Resins: Influence of Temperature on Retention

“…Adsorption of Cyt into the three chromatographic resins is entropically driven. Despite entropically driven adsorption being generally unexpected in ion exchangers, this was reported in the literature for different protein ion-exchangers combinations. ,, Entropic increases are often related to protein structural rearrangements , and, more importantly, the release of water molecules and counterions ,,− from the protein and solid-phase surface. The disruption of water structures and the subsequent release of the disordered water molecules to the bulk solution is responsible for the large entropy increases in the ion-exchange processes.…”

Mass spectrometry: Future opportunities for profiling and imaging steroids and steroid metabolites

“…A further benefit of LC over GC is the ability to include conjugates in the analyte profile [22]. Moreover steroids are now an integral part of metabolomics screens [23] e.g. cancer biomarkers.…”