title: Protein denaturation detected by time-of-flight secondary ion mass spectrometry.
abstract: In the present work we investigate the denaturation of a functional protein, horseradish peroxidase (HRP), under various experimental conditions using time-of-flight secondary ion mass spectrometry. HRP was immobilized on TiO(2), and the samples were stored under different conditions. The activity of the enzyme was assessed colorimetrically and compared to ToF-SIMS spectra. We show that denaturation of the protein can be monitored using the ToF-SIMS signal of the disulfide bonds, which is related to the tertiary structure of the protein. As disulfide bonds appear in a vast range of proteins, the present findings may be of wide significance; i.e., a tool is provided that can allow the investigation of the presence of an active protein structure by a comparably simple surface analytical method.
authors.affiliation: Department of Materials Science and Engineering 4, Chair for Surface Science and Corrosion, Friedrich-Alexander-University of Erlangen-Nuremberg, Martensstr.7, 91058 Erlangen, Germany.
authors.forename: Manuela S
authors.initials: MS
authors.lastname: Killian
authors.forename: Heike M
authors.initials: HM
authors.lastname: Krebs
authors.forename: Patrik
authors.initials: P
authors.lastname: Schmuki
mesh_terms: D003124:Colorimetry; D006735:Horseradish Peroxidase / Q000737:chemistry; D011489:Protein Denaturation; D018629:Spectrometry, Mass, Secondary Ion / Q000379:methods*; D014025:Titanium / Q000737:chemistry
chemical_list: C009495:titanium dioxide; D014025:Titanium; D006735:Horseradish Peroxidase