The Role of Electrostatic Forces in Anomalous Adsorption Behavior of Phosvitin at the Air/Water Interface

The role of metal ions in emulsion characteristics and flocculation behaviour of phosvitin-stabilised emulsions

“…At these last pH values, we did not observe any flocculation process contrasting with caseinate-stabilised emulsions under pH 5.5 as showed by Dickinson (2006). This is because Pvt, even at pH 4.0, is not still at its isoelectric point, and presents negative charge (Damodaran & Xu, 1996;Joubert & Cook, 1958). Consequently, the diminution in electrostatic repulsion is not enough to allow van der Waals interactions to stabilise a flocculated system.…”

Moderate conformational impact of citrate on ovotransferrin considerably increases its capacity to self-assemble at the interface

“…However, we can observe that in the presence of citrate, a weak barrier to adsorption is revealed by the first decrease of the surface pressure before the usual increase of the surface pressure with the surface concentration. This phenomenon, known as the ''image charge effect'' has been mentioned by others [29,42,[52][53][54][55][56]. This barrier effect was already observed for ovotransferrin at pH 6.5 but non-existent at pH 8.0 [33].…”

Phosvitin–calcium aggregation and organization at the air–water interface

“…These authors calculated that phosvitin made a loop (residues 50-200) in the aqueous phase whereas the extremities (residues 0-50 and 205-216) were in contact with the air-water interface. The second hypothesis favoured by Damodaran and Xu [5] is that phosvitin is hung on at the interface by only one hydrophobic end and the remainder of the molecule would be unfold in the subphase. For these authors, this could explain the adsorption of phosvitin in spite of the high electrostatic energy barrier due to its polyanionic character.…”

“…Of the known proteins, it is the most phosphorylated one with 50% of phosphoserines [3,4] inducing an important negative net charge of about −179 [5]. The phosphoserines are arranged in a singular way, forming numerous blocks in the centre of the sequence that can carry up to 15 consecutive residues, whereas the C-terminal and Nterminal extremities are relatively rich in hydrophobic amino acids [6,7].…”