The identification of archaeological eggshell using peptide markers

Abstract

Avian eggshell survives well in alkaline and neutral soils, but its potential as an archaeological resource remains largely unexplored, mainly due to difficulties in its identification. Here we exploit the release of novel bird genomes and, for the first time on eggshell, use MALDI-ToF (matrix-assisted laser desorption ionisation-time of flight) mass spectrometry in combination with peptide sequencing by LC-MS/MS. The eggshell proteome is revealed as unexpectedly complex, with 5755 proteins identified for a reference collection comprising 23 bird species. We determined 782 m/z markers useful for eggshell identification, 583 of which could be assigned to known eggshell peptide sequences. These were used to identify eggshell fragments recovered from a medieval site at Freeschool Lane, Leicester. We discuss the specificity of the peptide markers and highlight the importance of assessing the level of taxonomic identification achievable for archaeological interpretation.

“1984”: What Orwell could not predict. Proteomic analysis of his scripts

“…Presslee et al. [29] identified archaeological eggshells via peptide markers sequenced by LC‐MS/MS. The eggshell proteome, comprising 5755 proteins, is highly complex, thus, these authors determined 782 m/z peptide markers useful for eggshell identification.…”

Palaeoproteomic analysis of Pleistocene cave hyenas from east Asia

“…The extraction procedure was modified from references 53 , 54 . In brief, approximately 200 mg of bone or dentine powder was demineralized in 0.6 M HCl.…”

Ancient protein analysis in archaeology

“…This revealed that the most likely taxonomic origin for the beads was Nucella or Antalis , both found locally, suggesting a local manufacturing, rather than long-distance trade of these precious personal ornaments. More recently, MS approaches have additionally been applied to the analysis of avian eggshells ( 19 – 22 ) and marine and freshwater mollusk shells ( 23 ) to reveal insight into the use, manufacturing practices, and trade of local or exotic shell raw material and ornaments.…”

“…The approach was built upon work that examined the taxonomic origin of pelts, furs, feathers, and other animal products to aid in the identification of animal product trade and import/export ( 51 ). For archeological questions, this analysis not only is typically applied to fragmented or morphologically nondiagnostic bone fragments but also has been applied to a range of other archeological material culture, including parchments ( 52 – 54 ), ivory ( 55 ), eggshell ( 19 , 22 ), combs ( 56 ), and leather objects ( 57 ).…”