title: Spreading of proteins and its effect on adsorption and desorption kinetics.
abstract: The kinetics of adsorption of lysozyme and alpha-lactalbumin from aqueous solution on silica and hydrophobized silica has been studied. The initial rate of adsorption of lysozyme at the hydrophilic surface is comparable with the limiting flux. For lysozyme at the hydrophobic surface and alpha-lactalbumin on both surfaces, the rate of adsorption is lower than the limiting flux, but the adsorption proceeds cooperatively, as manifested by an increase in the adsorption rate after the first protein molecules are adsorbed. At the hydrophilic surface, adsorption saturation (reflected in a steady-state value of the adsorbed amount) of both proteins strongly depends on the rate of adsorption, but for the hydrophobic surface no such dependency is observed. It points to structural relaxation ("spreading") of the adsorbed protein molecules, which occurs at the hydrophobic surface faster than at the hydrophilic one. For lysozyme, desorption has been studied as well. It is found that the desorbable fraction decreases after longer residence time of the protein at the interface.
authors.affiliation: Laboratory of Physical Chemistry and Colloid Science, Wageningen University, Dreijenplein 6, 6703 HB Wageningen, The Netherlands.
authors.forename: Marijn
authors.initials: M
authors.lastname: van der Veen
authors.forename: Martien Cohen
authors.initials: MC
authors.lastname: Stuart
authors.forename: Willem
authors.initials: W
authors.lastname: Norde
mesh_terms: D000327:Adsorption; D000818:Animals; D002645:Chickens; D005260:Female; D007700:Kinetics; D007768:Lactalbumin / Q000493:pharmacokinetics*; D009113:Muramidase / Q000493:pharmacokinetics*; D012822:Silicon Dioxide
chemical_list: D012822:Silicon Dioxide; D007768:Lactalbumin; D009113:Muramidase