Protein adsorption at charged surfaces: the role of electrostatic interactions and interfacial charge regulation

Rune A. Hartvig, Marco Van De Weert, Jesper Østergaard, Lene Jorgensen, Henrik Jensen*

*Corresponding author for this work

    Research output: Contribution to journalJournal articleResearchpeer-review

    203 Citations (Scopus)

    Abstract

    The understanding of protein adsorption at charged surfaces is important for a wide range of scientific disciplines including surface engineering, separation sciences and pharmaceutical sciences. Compared to chemical entities having a permanent charge, the adsorption of small ampholytes and proteins is more complicated as the pH near a charged surface can be significantly different from the value in bulk solution. In this work, we have developed a phenomenological adsorption model which takes into account the combined role of interfacial ion distribution, interfacial charge regulation of amino acids in the proximity of the surface, electroneutrality, and mass balance. The model is straightforward to apply to a given set of experimental conditions as most model parameters are obtained from bulk properties and therefore easy to estimate or are directly measurable. The model provides a detailed understanding of the importance of surface charge on adsorption and in particular of how changes in surface charge, concentration, and surface area may affect adsorption behavior. The model is successfully used to explain the experimental adsorption behavior of the two model proteins lysozyme and α-lactalbumin. It is demonstrated that it is possible to predict the pH and surface charge dependent adsorption behavior from experimental or theoretical estimates of a preferred orientation of a protein at a solid charged interface.

    Original languageEnglish
    JournalLangmuir
    Volume27
    Issue number6
    Pages (from-to)2634-2643
    Number of pages10
    ISSN0743-7463
    DOIs
    Publication statusPublished - 15 Mar 2011

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