Mass spectrometry imaging of ancient teeth proteomes

In order to research the variation in protein distribution in teeth, proteins were extracted from archaeological (15-18th century, Netherlands) and modern teeth and identified using LC-MS/MS. Of the recovered proteins we then visualised the distribution of collagen type I (both the alpha-1 and -2 chains), alpha-2-HS-glycoprotein, haemoglobin subunit alpha and myosin light polypeptide 6 using MALDI-MSI. We found distinct differences in the spatial distributions of different proteins as well as between some peptides of the same protein. The reason for these differences in protein spatial distribution remain unclear, yet this study highlights the ability of MALDI-MSI for visualisng the spatial distribution of proteins in archaeological biomineralised tissues. Therefore MALDI-MSI might prove a useful tool to improve our understanding of protein preservation as well as aid in deciding sampling strategies.