Guckeisen T, Hosseinpour S, Peukert W (2019)
Publication Language: English
Publication Type: Journal article, Original article
Publication year: 2019
Book Volume: 35
Pages Range: 5004-5012
Journal Issue: 14
DOI: 10.1021/acs.langmuir.9b00311
Electrostatic interactions play essential roles in determining the function, colloidal stability, and adsorption of proteins on different surfaces and interfaces. Therefore, a molecular level understanding of the charge state of the proteins under different conditions is required to explain their macroscopic properties. In this study we have employed an inherently surface sensitive spectroscopic tool, sum frequency generation spectroscopy, to determine the charge state of a wide range of proteins as a function of pH at the liquid/air interface via measurement of the degree of orientation of water molecules. We compared the isoelectric point of the 12 investigated proteins at the liquid/air interface with that in the bulk solution obtained through zeta potential measurements. Ellipsometry is performed to determine the film thickness at the liquid/air interface at different charge states. In particular, protein aggregation at the isoelectric point is reflected by increased film thickness. For all proteins, the interfacial point of zero charge is close (with less than 1 pH unit variation) to that in the bulk solution.
APA:
Guckeisen, T., Hosseinpour, S., & Peukert, W. (2019). Isoelectric points of proteins at the air/liquid interface and in solution. Langmuir, 35(14), 5004-5012. https://dx.doi.org/10.1021/acs.langmuir.9b00311
MLA:
Guckeisen, Tobias, Saman Hosseinpour, and Wolfgang Peukert. "Isoelectric points of proteins at the air/liquid interface and in solution." Langmuir 35.14 (2019): 5004-5012.
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