Electrostatic interactions in protein adsorption probed by comparing lysozyme and succinylated lysozyme.
The influence of electrostatic interactions on protein adsorption was studied by comparing the adsorption of lysozyme and succinylated lysozyme at silica surfaces. The succinylation affects the charge of the protein, but also the stability. Although changes in stability can have an influence on adsorption, our data show that the primary effect can be entirely understood in terms of electrostatic interactions. The adsorbed amount as a function of pH has a maximum for both proteins. This maximum coincides with the isoelectric point for succinylated lysozyme, and is close to the isoelectric point for lysozyme. At pH values where the protein is electrostatically repelled by the sorbent, higher ionic strengths increase adsorption, and for electrostatic attraction higher ionic strengths decrease adsorption.
van der Veen
Marijn
M
Laboratory of Physical Chemistry and Colloid Science, Wageningen University, Dreijenplein 6, 6703 HB Wageningen, The Netherlands. marjin.vanderveen@wur.nl
Norde
Willem
W
Stuart
Martien Cohen
MC
D000327:Adsorption; D006863:Hydrogen-Ion Concentration; D009113:Muramidase / Q000737:chemistry*; D009994:Osmolar Concentration; D011506:Proteins / Q000737:chemistry*; D012822:Silicon Dioxide / Q000737:chemistry; D055672:Static Electricity; D013386:Succinates / Q000737:chemistry*; D013499:Surface Properties; D013997:Time Factors
D011506:Proteins; D013386:Succinates; D012822:Silicon Dioxide; D009113:Muramidase