Richard W. Hagan

Limits of Integration: Dietary Proteins in Human Dental Calculus

Richard W. Hagan§, Christina G. Warinner§, Jessica L. Hendy§

§ Kahlaische Straße 10 07745 Jena, Germany

Human dental calculus contains an abundance of ancient DNA and proteins. Recent research has exploited this fact to explore and test hypotheses about several aspects of the human past through different approaches, including the use of liquid chromatography tandem mass spectrometry (LC-MS/MS) for the detection and identification of dietary proteins that were incorporated into the calculus of an individual during their lifetime. This method has resulted in the positive identification of proteins from milk as well as cereals and other plants, however the overall abundance of dietary proteins tends to make up only a small part of the recovered calculus metaproteome, which is largely dominated by bacterial protein identifications. Little is known about the mechanisms that dictate the frequency at which dietary proteins are incorporated into the biofilm that eventually becomes dental calculus, or why certain proteins, such as β-lactoglobulin from milk, are more commonly identified than others. This presentation will cover theoretical limits for the inclusion of dietary proteins into dental calculus in the context of biofilm formation, dietary variety, and meta-analysis of existing datasets. Additionally, it will propose future directions for researchers interested in understanding the mechanisms involved in the persistence or degradation of dietary proteins in calculus over time. Human dental calculus remains an exciting source of proteomic information about the human past, and improving our understanding of its properties will enhance our ability to utilize this unique resource for archaeological science.