Identification of Protein Remains in Archaeological Potsherds by Proteomics
- 22 May 2008
- journal article
- Published by American Chemical Society (ACS) in Analytical Chemistry
- Vol. 80 (12), 4590-4597
- https://doi.org/10.1021/ac800515v
Abstract
We demonstrate here the possibility of identifying proteins trapped in few milligrams of the clay matrix of a 1200-1400 AD Iñupiat potsherd fragment from Point Barrow, Alaska, by a dedicated proteomics approach. The four main steps of a proteomics analysis, (i) protein extraction from biological samples, (ii) protein hydrolysis using a hydrolase enzyme, (iii) nanoLC, nanoESI MS, and MS/MS analysis of the generated peptides, and (iv) protein identification using protein databank proceeded from genomic data, have been optimized for archeological remains. Briefly our procedure starts by grinding the potsherds, extraction with 1% trifluoroacetic acid, digestion with excess of trypsin, nanoLC, nanoESI FT-ICR analysis, and data mining by homology search. The developed conditions were evaluated on protein extracts from remains obtained by heated muscle tissues and blubbers of different seal and whale species, these samples representing the main diet sources of the Eskimo population. Most of the proteins were identified by sequence homology to other species due to the lack of cetacean and pinniped proteins in the databanks. More interestingly, two proteins, myoglobin and hemoglobin, respectively, identified in muscle tissue samples and blubber samples highlight several specific peptides of cetacean and pinniped species; these peptides are significant to prove the presence of these marine species in the analyzed samples. Based on the developed methodology and on protein identification results obtained from the heated seal/whale muscle tissues and blubbers, the analysis of the clay matrix of a 1200-1400 AD Iñupiat potsherd fragment from Point Barrow was investigated. The described method succeeds in identifying four peptides corresponding to the harbor seal myoglobin (species Phoca vitulina) with a measured mass accuracy better than 1 ppm (MS and MS/MS experiments) including one specific peptide of the cetacean and pinniped species and one specific peptide of the seal species. These results highlight, for the first time, a methodology able to identify proteins from a few milligrams of archeological potsherd buried for years; the obtained results confirm the presence of a seal muscle tissue protein in this Punuk potsherd.Keywords
This publication has 27 references indexed in Scilit:
- Elucidation of molecular and elementary composition of organic and inorganic substances involved in 19th century wax sculptures using an integrated analytical approachAnalytica Chimica Acta, 2006
- Characterisation of proteinaceous binders in artistic paintings by chromatographic techniquesJournal of Separation Science, 2004
- Structural characterization of lipid constituents from natural substances preserved in archaeological environmentsMeasurement Science and Technology, 2003
- Characterization of Archaeological Beeswax by Electron Ionization and Electrospray Ionization Mass SpectrometryAnalytical Chemistry, 2002
- Chemistry of Archaeological Animal FatsAccounts of Chemical Research, 2002
- Identification of Archaeological Adhesives Using Direct Inlet Electron Ionization Mass SpectrometryAnalytical Chemistry, 2002
- Detecting milk proteins in ancient potsNature, 2000
- Proteinaceous Material from Potsherds and Associated SoilsJournal of Archaeological Science, 1996
- A study for the characterization of binding media from medieval polychrome sculptures by gas chromatography-mass spectrometryChromatographia, 1996
- Identification of archaeological blood proteins: A cautionarynoteJournal of Archaeological Science, 1995