Use of Hydroxyacetophenones as Matrices for the Analysis of High Molecular Weight Glutenin Mixtures by Matrix-assisted Laser Desorption/ Ionization Mass Spectrometry

A selection of hydroxyacetophenones has been investigated as matrices for the analysis, by matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS), of high molecular weight (HMW) glutenin mixtures from three wheat varieties. Mass spectra were obtained directly from the HMW glutenin extracts without any preliminary purification and separation steps. According to the quality of the mass spectra, obtained using different hydroxyacetophenones, it has been possible to classify the matrices on the basis of their suitability for the analyte properties. Only two of the matrices considered showed to be compatible with the HMW glutenin mixtures analysis, although a large amount of other highly complex protein mixtures are present. This study indicates that MALDI-MS, as a stand-alone technique, is particularly useful for the direct determination of the complete HMW subunits profile and their molecular weights.