AVS 51st International Symposium
    Biomaterial Interfaces Monday Sessions
       Session BI-MoP

Paper BI-MoP3
Architectured Surfaces for On-Probe Affinity Capture MALDI Mass Spectrometry

Monday, November 15, 2004, 5:00 pm, Room Exhibit Hall B

Session: Poster Session
Presenter: Z. Segu, University of Texas at Arlington
Authors: G.R. Kinsel, University of Texas at Arlington
Z. Segu, University of Texas at Arlington
R.B. Timmons, University of Texas at Arlington
Correspondent: Click to Email
MALDI MS is a powerful analytical tool for the characterization of proteins and peptides and is presently used extensively for the analysis of biomolecules extracted from biological media. In these applications one or more purification / fractionation steps are typically required prior to MALDI MS analysis. The development of affinity fractionation approaches performed directly on the MALDI probe is considered attractive because of shortened analysis time, inherent simplicity and reduced sample loss. However, a significant challenge for these on-probe affinity fractionation approaches is the limited capacity of the MALDI probe surface. The significance of protein solution concentration, surface-protein binding constant, and total protein surface capacity, with respect to the MALDI limit of detection for a given protein in a mixture, is revealed in theoretical studies utilizing the systematic treatment of equilibria. Additional experimental studies confirm the predictions of the theoretical model and reveal the importance of the MALDI probe capacity on protein detection using modified probes. In addition, a novel method to increase the capacity of modified MALDI probes is presented. In this approach gold particles are attached to allyl amine RF plasma polymer modified MALDI probes and subsequently modified to incorporate affinity capture ligands through the attachment of biotinylated alkane thiols. Preliminary data demonstrates that these modified gold bead attached MALDI probes allow the selective capture of targeted biomolecules and offer significant increases in the biomolecular binding capacity of the MALDI probe surface.