Wamer, Nathan C; Morse, Chase N; Gadient, Jennifer N; Dodson, Taylor A; Carlson, Eric A; Prestwich, Erin G
description
<p><span style="font-size:10pt;color:rgb(83%,12%,14%);">ABSTRACT: </span><span style="font-size:10pt;">Different bacterial cell surface associated biomole-<br>cules can be analyzed by matrix-assisted laser desorption ionization<br>time-of-flight (MALDI-TOF) mass spectrometry and coupled with<br>collision induced dissociation (CID) for identification. </span><span style="font-size:10pt;font-style:italic;">Pseudomo-<br>nas aeruginosa </span><span style="font-size:10pt;">is an opportunistic, Gram-negative bacterium that<br>causes acute or chronic biofilm infections. Cells of </span><span style="font-size:10pt;font-style:italic;">P. aeruginosa<br></span><span style="font-size:10pt;">communicate through a system of signaling biomolecules known as<br>quorum sensing (QS). The QS system can result in the production<br>of biosurfactant rhamnolipids known to associate and alter the<br>cellular membrane. MALDI-TOF utilizes a variety of matrices that<br>can interact differently with biomolecules for selective ionization.<br>We examined six common matrices to determine the optimal<br>matrix specific to different molecule classes in </span><span style="font-size:10pt;font-style:italic;">P. aeruginosa<br></span><span style="font-size:10pt;">associated with cell surfaces. Three major molecule classes (quinolones, rhamnolipids, and phospholipids) were observed to ionize selectively with the different matrices tested. Sodiated and protonated adducts differed between matrices utilized in our study. Isobaric ions were identified as different molecule classes depending on the matrix used. We highlight the role of matrix selection in MALDI-TOF identification of molecules within a complex biological mixture. </span></p>