Relationship between the protein surface hydrophobicity and its partitioning behaviour in aqueous two-phase systems of polyethyleneglycol–dextran

Novel Aqueous Two-Phase Systems Formed by Biocompatible and Biodegradable Polysaccharides and Acetonitrile

“…However, for dextran concentrations above 17 wt% the K van values are almost constant, considering the associated standard. This trend suggests the presence of a saturation process linked to the dextran concentration, as reported by Tubio et al, (2004) in the albumin partitioning behavior using a PEG-3350/dextran ATPS. The recovery values of vanillin at the ACN-rich phase range between 71.61 and 77.07 %, values lower than that those found by us (98.37 and 99.94 %) using ATPS constituted by alcohols and potassium phosphate salts (Reis et al, 2012).…”

“…, 2012). This homopolymer of glucose has been applied as a constituent in aqueous two-phase system -ATPS (Tubio et al, 2004). ATPS are usually formed by mixing two polymers in aqueous media (PEG and DextranKarakatsanis and Liakopoulou-Kyriakides, 2007); or by one polymer and one salt (PEG and phosphate-based salts -Lima et al, 2002).…”

Macromolecular Crowding and Confinement: Biochemical, Biophysical, and Potential Physiological Consequences

“…It has long been evident that PEG fractions with molecular weights in excess of a few thousand have a large and predominantly repulsive interaction with proteins, and tend to induce macromolecular associations and compaction in qualitative accord with crowding theory (see for example (36,67) and works cited in Tables 1-5). However, a number of studies have shown that this interaction cannot be described quantitatively in terms of excluded volume alone, and several independent lines of evidence point to an attractive interaction between PEG and nonpolar or hydrophobic sidechains on the protein surface (5,6,50,83,84). Thus the repulsive excluded volume contribution to PEG-protein interaction is partially compensated to an unknown extent by an attractive interaction, the strength of which can vary significantly between different proteins of approximately equal size.…”

Wrap-and-Strip Technology of Protein–Polyelectrolyte Complex for Biomedical Application

“…PEG is now known to confer a salting-out effect as a preferentially excluded compound on the native protein, similar in nature to glycerol [100] and sugars [101]. It is noted that PEG tends to bind to hydrophobic protein surfaces at elevated temperatures [102][103][104]. The third point also relates to irreversible aggregate formation between thermally unfolded molecules.…”