Extended Data Fig. 4: Preservation of the Xiahe dentine proteome.
From: A late Middle Pleistocene Denisovan mandible from the Tibetan Plateau
a, Deamidation of five Xiahe proteins also identified in several proteomes from Middle and Late Pleistocene fossils. b, Glutamine deamidation of peptide P1105 observed in the zooarchaeology by mass spectrometry (ZooMS) analysis of the Xiahe dentine sample compared to reference data. n = number of specimens included. c, Correlation between deamidation observed in LC–MS/MS experiments for ammonium bicarbonate (AmBic) and acid-demineralization (Acid) extracts (R2 = 0.99). d, Length distribution of non-tryptic peptides in a Late Pleistocene Neanderthal and the Xiahe dentine proteome. AA, amino acids. Violins stretch from the minimum to the maximum value; box plots indicate the median (middle line), 25% and 75% (boxes) and stretch to 1.5× the interquartile range (whiskers). n = number of unique spectra included. Deamidation is based on quantitative MALDI–TOF-MS analysis (b) or semiquantitative LC–MS/MS spectral counting methods (a, c). ‘0%’ indicates an absence of deamidation and ‘100%’ indicates complete deamidation of asparagine and glutamine. a, d, Combined data for all six LC–MS/MS runs conducted on the Xiahe protein extracts. c, Combined data from the three replicates per extraction method. Samples are colour-coded according to geological age. Data were obtained from previous studies21,54,55,66.
