AVS 49th International Symposium
    Biomaterials Monday Sessions
       Session BI+VT-MoA

Paper BI+VT-MoA3
ToF-SIMS and XPS Analysis of Enzymatic Digests of Adsorbed Protein Films

Monday, November 4, 2002, 2:40 pm, Room C-201

Session: Protein Surface Interactions
Presenter: M.S. Wagner, University of Washington
Authors: M.S. Wagner, University of Washington
D.G. Castner, University of Washington
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Characterization of multicomponent adsorbed protein films is critical in understanding biological interactions with surfaces. We have previously shown that Time of Flight Secondary Ion Mass Spectrometry (ToF-SIMS) can quantify the composition of binary and ternary adsorbed protein films using the low mass (0 < m/z < 200) fragmentation pattern of the mass spectrum. However, quantification of more complex protein films using this method is limited to the most abundant proteins present in the films. Therefore, trypsin digestion of the adsorbed proteins was performed to generate tryptic fragments for subsequent analysis by ToF-SIMS. The tryptic fragments were identified by combining ToF-SIMS with matrices from Matrix Assisted Laser Desorption and Ionization Mass Spectrometry (MALDI-MS). Residual protein remaining on the substrate after digestion was detected using ToF-SIMS and X-ray Photoelectron Spectroscopy (XPS). This method provides unique fragments for the identification of adsorbed proteins by ToF-SIMS.