pH effect on protein G orientation on gold surfaces and characterization of adsorption thermodynamics
The pH effect on adsorbed antibody-binding protein (protein G) orientation on gold (Au) and its adsorption thermodynamic characteristics were investigated using quartz crystal microbalance (QCM) and X-ray photoelectron spectroscopy (XPS). The adsorbed protein G orientation was measured by binding re...
| Veröffentlicht in: | Langmuir : the ACS journal of surfaces and colloids. - 1985. - 28(2012), 17 vom: 01. Mai, Seite 6928-34 |
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| Format: | Online-Aufsatz |
| Sprache: | English |
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2012
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| Zugriff auf das übergeordnete Werk: | Langmuir : the ACS journal of surfaces and colloids |
| Schlagworte: | Journal Article Research Support, U.S. Gov't, Non-P.H.S. Antibodies Bacterial Proteins IgG Fc-binding protein, Streptococcus Serum Albumin, Bovine 27432CM55Q Gold 7440-57-5 |
| Zusammenfassung: | The pH effect on adsorbed antibody-binding protein (protein G) orientation on gold (Au) and its adsorption thermodynamic characteristics were investigated using quartz crystal microbalance (QCM) and X-ray photoelectron spectroscopy (XPS). The adsorbed protein G orientation was measured by binding response of two antibody-antigen systems: the model bovine serum albumin (BSA) and the foodborne pathogen E. coli O157:H7. Surface coverage was not significantly affected by pH, but its orientation was. The most properly oriented protein G for antibody binding was achieved at near-neutral pH. Adsorption was verified by XPS measurements using nitrogen (N) 1s, oxygen (O) 1s, and Au 4p peak heights. Adsorption energetics were determined by van't Hoff and Langmuir kinetic analyses of adsorption data obtained at 296, 303, and 308 K. Large characteristic entropy change of protein adsorption was observed (ΔS° = 0.52 ± 0.01 kcal/mol·K). The adsorption process was not classical physisorption but exhibited chemisorption characteristics based on significant enthalpy change (ΔH° = -25 ± 6 kcal/mol) |
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| Beschreibung: | Date Completed 17.08.2012 Date Revised 16.11.2017 published: Print-Electronic Citation Status MEDLINE |
| ISSN: | 1520-5827 |
| DOI: | 10.1021/la3009128 |