Linking structural and compositional changes in archaeological human bone collagen: an FTIR‑ATR approach
Metadatos
Mostrar el registro completo del ítemEditorial
NATURE RESEARCH
Fecha
2020Referencia bibliográfica
Martínez Cortizas, A., López-Costas, O. Linking structural and compositional changes in archaeological human bone collagen: an FTIR-ATR approach. Sci Rep 10, 17888 (2020). https://doi.org/10.1038/s41598-020-74993-y
Patrocinador
Project "Galician Paleodiet" ED481D 2017/014; Consiliencia network ED 431D2017/08; GPC ED341B 2018/20; "Antropoloxia dos restos oseos humanos de Galicia" (Direccion Xeral de Patrimonio Historico), Xunta de Galicia; Plan Galego I2C mod.B ED481D 2017/014; Instituto de Salud Carlos III Spanish Government PID2019-111683RJ-100Resumen
Collagen is the main structural and most abundant protein in the human body, and it is routinely
extracted and analysed in scientifc archaeology. Its degree of preservation is, therefore, crucial
and several approaches are used to determine it. Spectroscopic techniques provide a cost-efective,
non-destructive method to investigate the molecular structure, especially when combined with
multivariate statistics (chemometric approach). In this study, we used FTIR-ATR spectroscopy to
characterise collagen extracted from skeletons recovered from necropoleis in NW Spain spanning
from the Bronze Age to eighteenth century AD. Principal components analysis was performed on
a selection of bands and structural equation models (SEM) were developed to relate the collagen
quality indicators to collagen structural change. Four principal components represented: (i) Cp1,
transformations of the backbone protein with a residual increase in proteoglycans; (ii) Cp2, protein
transformations not accompanied by changes in proteoglycans abundance; (iii) Cp3, variations
in aliphatic side chains and (iv) Cp4, absorption of the OH of carbohydrates and amide. Highly
explanatory SEM models were obtained for the traditional collagen quality indicators (collagen yield,
C, N, C:N), but no relationship was found between quality and δ13C and δ15N ratios. The observed
decrease in C and N content and increase in C:N ratios is controlled by the degradation of protein
backbone components and the relative preservation of carbon-rich compounds, proteoglycans and, to
a lesser extent, aliphatic moieties. Our results suggest that FTIR-ATR is an ideal technique for collagen
characterization/pre-screening for palaeodiet, mobility and radiocarbon research.