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Protein Digestion, Ultrafiltration, and Size Exclusion Chromatography to Optimize the Isolation of Exosomes from Human Blood Plasma and Serum
Published on: April 13, 2018
Study of the serum albumin-polyethyleneglycol interaction to predict the protein partitioning in aqueous two-phase
Beatriz Farruggia1, Bibiana Nerli, Guillermo Picó
1Facultad de Cs. Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, CIUNR and CONICET (2000), Rosario, Argentina.
Abstract:
The theoretical framework based only on the excluded volume forces is not enough to explain the bovine serum albumin partitioning behaviour in aqueous biphasic systems. The goal of this work is to look at the phase separation via the polymer effect on the water structure. Our findings suggest that polyethyleneglycol 600-protein interaction is conducted by van der Waals forces between the hydrophobic surfaces from PEG and protein molecules, which implies the rupture of hydrogen bonds from the structured water in their neighbours. Therefore, the protein will concentrate in the most water-structured phase (polyethyleneglycol) in order to reach the minimal free energy condition. When polyethyleneglycol molecular weight increases, its exclusion from protein surface prevails, thus pushing the bovine serum albumin to the bottom phase.
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