Shotgun identification of protein modifications from protein complexes and lens tissue

摘要: Large-scale genomics has enabled proteomics by creating sequence infrastructures that can be used with mass spectrometry data to identify proteins. Although protein sequences deduced from nucleotide sequences, posttranslational modifications proteins, in general, cannot. We describe a process for the analysis of is simple, robust, and applied complicated mixtures. A or mixture digested using three different enzymes: one cleaves site-specific manner two others cleave nonspecifically. The peptides separated multidimensional liquid chromatography analyzed tandem spectrometer. This approach been modification analyses proteins simple mixture, Cdc2p complexes isolated through use an affinity tag, lens tissue patient congenital cataracts. Phosphorylation sites have detected known stoichiometry as low 10%. Eighteen four types on five which were previously unreported. Three yielded eight containing modifications. In tissue, 270 identified, 11 crystallins found contain total 73 modification. Modifications identified crystallin included Ser, Thr, Tyr phosphorylation, Arg Lys methylation, acetylation, Met, Tyr, Trp oxidations. method presented will useful discovering co-