Proteomic study of Anton Chekhov' letters

Five different letters and post cards as well as the shirt worn by Anton Chekhov on his death bed, stored in A. Chekhov’s museum in Melikhovo (nearby Moscow), have been analyzed by applying to these surfaces EVA (an ethyl vinyl acetate foil studded with crushed strong anion and cation exchangers and with C8 resins) diskettes. Three different eluates (under acidic and basic conditions and with acetonitrile) were analyzed by high resolution mass spectrometry. The environmental microbiota present on samples and the M. ycobacterium Tuberculosis tuberculosis strain were described by a meta-proteomics approach. Eight identified M. Tuberculosis tuberculosis proteins confirmed the presence of the bacterium and the cause of Chekhov death, in addition to several sequenced peptides belonging to other bacterial species. The human plasma proteins and human keratins, detected on a tiny blood spot on the shirt, demonstrated the power of the combined approach.