Protein identification and characterization Identification and characterization with peptide mass fingerprinting data FindMod - Predict potential protein post-translational modifications and potential single amino acid substitutions in peptides. Experimentally measured peptide masses are compared with the theoretical peptides calculated from a specified Swiss-Prot entry or from a user-entered sequence, and mass differences are used to better characterize the protein of interest. FindPept - Identify peptides that result from unspecific cleavage of proteins from their experimental masses, taking into account artefactual chemical modifications, post-translational modifications (PTM) and protease autolytic cleavage Mascot - Peptide mass fingerprint from Matrix Science Ltd., London PepMAPPER - Peptide mass fingerprinting tool from UMIST, UK ProFound - Search known protein sequences with peptide mass information from Rockefeller and NY Universities [or from