What proteomics can do for cultural heritage

WHAT PROTEOMICS CAN DO FOR CULTURAL HERITAGE? Gabriella Leo, Piero Pucci, Gennaro Marino, Leila Birolo. Dipartimento di Chimica Organica e Biochimica, Università di Napoli “Federico II”, Napoli, Italy. In the context of artistic and historic objects, the identification of proteins is still a challenging task, because of the very low amount of sample available, because of the complex and quite variable chemical composition of the paints, because of the possible simultaneous presence of several components, and because of degradation of the original materials as a result of aging and pollution. We proposed to adapt proteomic strategies for the identification of proteins in binders of paintings, but also in seeds, food remains in archeological find, etc.., to overcome requirements and difficulties presented by specific samples. In particular, tryptic hydrolysis in heterogeneous phase, followed by the analysis by LC-MS/MS, was successfully used to unambiguously identify milk proteins in a sample from a painting decorating the vaults of the upper church in the Basilica of St. Francis in Assisi (Leo et al., 2009). Moreover, similar strategies were exploited for the characterization of the natural and unnatural aging products in masterpieces. We identified deamidation as a major modifications of proteins in binders, that could be related to the aging of artistic and historic objects (Leo et al., in preparation). The systematic analysis of samples from the 14th century frescoes of the Monumental Cemetery in Pisa indicate extensive deamidation occurring on most of the peptides identified, suggesting that the miniature molecular clock, as Robinson and Robinson defined any amide residue present in peptides or proteins (2004), might well be used as molecular marker in artworks