PERSONAL DE APOYO
NEME TAUIL Ricardo Martin
congresos y reuniones científicas
Título:
MALDI-MS and LC-Orbitrap combined strategy proves that a mid-XIXth century etnohistorical document from Northern Patagonia was written with human blood
Autor/es:
NEME TAUIL, RICARDO MARTÍN; NAZAR, MARIANA; PEDROTTA, VICTORIA; SCHMID, CAROLINA; MORENO DE COLONNA, SILVIA
Lugar:
Acapulco
Reunión:
Simposio; 8th Symposium of the Mexican Proteomics Society - 3rd PanAmerican-Human Proteome Organization (Pan-HUPO) Meeting - 2nd Ibero-American Symposium on Mass Spectrometry; 2019
Institución organizadora:
Sociedad Mexicana de Proteómica - PanAmerican-Human Proteome Organization (Pan-HUPO)
Resumen:
The National Archives in Argentina guards a letter written in 1856 by cacique Yanquetruz, a young influential indigenous leader from Northern Patagonia willing to negotiate both with the State of Buenos Aires and the Confederación, in a context of high interethnical conflict, changing alliances and territorial reshaping some few years before the Argentine State was born. According to text, where kind requests are intertwined with explicit menaces, his very own blood had been used to write the letter in order to show how poor his people were as they could not even afford buying ink. Literature has long repeated this statement, crucial in understanding frequently ignored indigenous agency, with no actual proof. Evaluating the presence of human blood required a highly sensitive technique as regular forensic methods were too destructive for the document and are also not suitable for such old samples. A very small amount of the body of the text was scraped out with the tip of a scalpel. The first step required finding an appropriate way of dissolving it. After several attempts, a mixture of surfactants, salts and detergents previously set up in our laboratory successfully did the task. Following enrichment, trypsin digestion and desalting, peptides were analysed by MALDI-ToF-ToF. This first approach strongly suggested the presence of alpha and beta subunits of human hemoglobin in the sample. However statistically significant these results were, further confirmation was needed as these peptide sequences are highly conserved along evolution and they only referred to one protein of serum. Not only nHPLC-ESI-Orbitrap analysis identified the presence of several other different proteins from blood but also the species was confirmed by unique peptides not shared with other mammalian proteins. Besides hemoglobin, of which alpha, beta, gamma and even delta chains were present in the sample, some remarkable examples are serum albumin identified by 31 unique peptides of which 24 were not present in other mammals, alpha-2-macroglobulin with 13 unique peptides of which 11 were exclusive from human, serotransferrin with 9 unique peptides of which 8 were not in other mammals, and fibrinogen alpha-chain identified by 8 unique peptides of which 7 were exclusively human. Interestingly, the novelty of the results, the transdisciplinarity of the work -where proteomics turned out to be a key feature to contribute with unambiguous information-, and its etnohistorical implications for peoples who inhabit Argentine territory and still face problems such as land tenure, were able to call some media attention and eventually led to the production of a video-documentary about the research.