Transferable Mass Spectrometry Methods: Forensics in Time: Palaeoproteomics

Abstract

The information that defines all organisms, including humans, is encoded in their DNA, which altogether comprises the genotype. Throughout life, from initial organ formation to later lifestyle exposures, different genes are epigenetically activated and transcribed into mRNA, which is in turn translated into proteins that make up the final phenotype. Therefore, proteins are the most prominent source of phenotypic information and have consequently been exhaustively studied in different contexts, including clinical biomarker discovery for diseases. Despite the fact that proteins are extremely stable biomolecules that can hold phenotypic information over thousands of years, their potential in forensic and archaeological research has not yet been fully exploited. At least in part, this is due to the fact that the field of proteomics has mainly focused on fundamental molecular biology and medical applications, developing tools to maximize the number of peptide identifications in tryptic digests of (liquid) biopsies and cell cultures, which are very different from the sparse and heavily modified peptide mixtures often originating from unknown sources that need to be identified in forensic and archaeological contexts. Here, we describe the growing interest and recent developments in forensic proteomics and illustrate how palaeoproteomics, its equivalent for more ancient times, provides valuable methodological insights for future forensic applications.