In-situ enrichment of phosphopeptides on MALDI plates modified by ambient ion landing

0382652 - MBÚ 2013 RIV GB eng J - Journal Article
Krásný, Lukáš - Pompach, Petr - Strohalm, Martin - Obšilová, Veronika - Strnadová, Marcela - Novák, Petr - Volný, Michael
In-situ enrichment of phosphopeptides on MALDI plates modified by ambient ion landing.
Journal of Mass Spectrometry. Roč. 47, č. 10 (2012), s. 1294-1302. ISSN 1076-5174. E-ISSN 1096-9888
R&D Projects: GA ČR GPP206/10/P018; GA ČR(CZ) GAP207/11/0455; GA ČR(CZ) GAP206/12/1150; GA MŠMT(CZ) ME10013; GA ČR(CZ) GD204/09/H084
Institutional support: RVO:61388971 ; RVO:67985823
Keywords : MALDI FTICR * phosphopetides * enrichment
Subject RIV: CE - Biochemistry
Impact factor: 3.214, year: 2012

We report substantial in-situ enrichment of phosphopeptides in peptide mixtures using titanium and zirconium dioxide-coated matrix assisted laser desorption-ionization (MALDI) plates prepared by recently reported ambient ion landing deposition technique. The technique was able to modify four common materials currently used for MALDI targets (stainless steel, aluminum, indium-tin oxide glass and polymeric anchor chip). The structure of the deposited dioxide was investigated by electron microscopy, and different surfaces were compared and discussed in this study. Two standard proteins were used to test the enrichment capabilities of modified MALDI plates: casein and in-vitro phosphorylated trehalase. The enrichment of casein tryptic digest resulted in identification of 20 phosphopeptides (including miscleavages). Trehalase was used as a suitable model of larger protein that provided more complex peptide mixture after the trypsin digestion. All four possible phosphorylation sites in trehalase were identified and up to seven phosphopetides were found (including methionine oxidations and miscleavages). Two different mass spectrometers, MALDI-Fourier transform ion cyclotron resonance (FTICR) and MALDI-time of flight, were used to detect the phosphopeptides from modified MALDI plates after the enrichment procedure. It was observed that the desorption-ionization phenomena on the modified surfaces are not critically influenced by the parameters of the different MALDI ion sources (e.g. different pressure, different extraction voltages), and thus the presence of dioxide layer on the standard MALDI plate does not significantly interfere with the main MALDI processes
Permanent Link: http://hdl.handle.net/11104/0215728