|Ren, Diya - PURDUE UNIVERSITY|
|Ohm, Herbert - PURDUE UNIVERSITY|
|Regnier, Fred - PURDUE UNIVERSITY|
Submitted to: International Triticeae Symposium Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: May 1, 2002
Publication Date: June 3, 2002
Citation: Anderson, J.M., Ren, D., Williams, C.E., Goodwin, S.B., Ohm, H.W., Regnier, F. 2002. Combining liquid chromatography with mass spectrometry to detect differential expression of proteins in plant-pathogen interactions. International Triticeae Symposium Proceedings. Technical Abstract: The reversible phosphorylation of specific proteins are involved in the regulation of many aspects of cell physiology, plant development and defense responses. However, detection of phosphorylated peptides in a complex mixture of other peptides is challenging due to their low abundance and poor MALDI-TOF ionization efficiency. In this study, by Ga(III) immobilized, metal affinity chromatography is optimized, phosphopeptides are enriched and then separated by reverse phase chromatography. Identification and mapping of the phosphorylation sites on the peptides are done by MALDI or ESI/MS with database searching based on the mass and sequence comparison. The combination of global isotope tagging by differential labeling with acetate and trideuteroacetate, and mass spectrometric peptide mass mapping can identify the up-down regulation of the phosphoproteins in pathogen-treated samples. This protocol has been used to study the changes in phosphoproteins in wheat leaves treated by the leaf pathogen Septoria tritici.