Other Tools Related to Protein Identification

Peptide masses that do not immediately match theoretical masses in the identification process, can not only be the result of a post-translational modification, but may arise during the processing of the sample. A tool that can identify possible peptides that have resulted from non-specific chemical or enzymatic cleavage of proteins is the FindPept tool (http //www.expasy.ch/tools/). 

At this point we would also like to mention a versatile tool to model mass spectra and mass fragmentation spectra in silico. A range of proteomics tools is combined in MassXpert, a free application by F. Rusconi, which can be downloaded from http //frl.lptc.u-bordeaux.fr). Supported features include cleavage of a protein by different enzymes, fragmentation of peptides or small proteins, an m/z calculator for a given protein mass and many more. 

---