Elena C. L. Rigantea, Simona A. Rigantia, Ludovico Geminianib, Laura Rampazzib, Tommaso R. I. Cataldia, Cosima Damiana Calvanoa

aDipartimento di Chimica, Università degli Studi di Bari Aldo Moro, 70126 Bari, Italy;
bCentro Speciale di Scienze e Simbolica dei Beni Culturali, Università degli Studi dell’Insubria, Via Sant’Abbondio 12, 22100 Como, Italy.

In recent years, chromatography coupled with mass spectrometry is gaining increasing importance in the field of the diagnostics of Cultural Heritage [1] for characterizing organic materials used in the creation of precious artworks [1, 2]. In this work, some samples of leather from Japanese armors were studied. The samples date back to the 16th and 19th centuries and belong to the Morigi collection, preserved at the Museo delle Culture (Lugano, Switzerland). The armors are composed of leather structures decorated with metal inserts and embellished with colored textile fibers. A few mg of leather fragments were collected and subjected to MALDI-ToF-MS and RPLC-ESI-MS investigations with a bottom-up proteomic approach aimed at determining their protein composition, especially the animal species. Indeed, this information can be useful to draw indications on the historical context such as past Japanese breeding habits. Three of the seven samples were assessed as animal collagen via MALDI peptide mass fingerprintings (PMF). Collagen speciation was performed via RPLC-ESI-dd-MS/MS runs which allowed the sequencing of multiple species-specifc peptides from cattle (Bos taurus) for two samples, and from sheep (Ovis aries) for one sample. Four other samples did not provide satisfactory results due perhaps to vegetal tanning treatments that prevent protein extraction and digestion. Thus, two extraction methods adapted from Li et al. [3] and Brandt et al. [4] were tested on expendable samples of modern tanned leather. 

The first method, which involves a step of dialysis, provided the best results and was further improved by using regenerated cellulose membranes filters (10 kDa molecular cut off) for the purification and digestion of the protein extracts. In this way it was possible to assess the bovine origin of the modern leather analyzed. This methodology will be applied to real samples to remove the tannin component and collect the proteomic information sought.

Acknowledgements: This work was supported by Progetto di Ricerca di Interesse Nazionale—PRIN 2022CNNRWZ- REActive GEl for orgaNic bindERs recognition in Artworks (REAGENERA), financed by the Italian Ministero per l’Istruzione, l’Università e la Ricerca (MIUR).

Keywords: Mass spectrometry, proteomics, chromatography, Cultural Heritage

References

1. Geddes da Filicaia E., Evershed R., et al., Analytica Chimica Acta, 1246 (2023), 340575 DOI: 10.1016/j.aca.2022.340575. 

2. Rigante E.C.L., Calvano C.D., et al., Microchemical Journal, 190 (2023), 108590 DOI: 10.1016/j.microc.2023.108590. 

3. Li L., Zhang M., et al., Polymers, 15 (2023), 3459 DOI: 10.3390/polym15163459. 

4. Brandt L., Schmidt A., et al., Plos ONE, 9 (2014), e106875 DOI: 10.1371/journal.pone.0106875.Cultural Heritage