This data was obtained from the PNNL database and it is supporting material for: Applying a Targeted Label-Free Approach Using LC-MS AMT Tags to Evaluate Changes in Protein Phosphorylation Following Phosphatase Inhibition. Feng Yang, N Jaitly, H Jayachandran, Q Luo, ME Monroe, X Du, MA Gritsenko, R Zhang, DJ Anderson, SO Purvine, JN Adkins, RJ Moore, HM Mottaz, SJ Ding, MS Lipton, DG Camp, HR Udseth, RD Smith, and S Rossie. Journal of Proteome Research; (2007) 6, 4489-4497. The data can be found here.
The data was acquired using an LTQ instrument. Phosphorylated peptides were enriched by first methylating the carboxyl groups in the peptides and then using an immobilized metal ion column. The peptide-to-spectrum assignments were made assuming methyl groups on all aspartic and glutamic acids, as well as all peptide C-termini. Phosphoryl groups were allowed as a possibility on serine, threonine and tyrosine residues.
The data is of good quality. It consists almost entirely of phosphopeptides. It also contains a significant number of peptide assignments that have not been previously observed. The observed proteins are predominantly nuclear and cytoplasmic.