UC Davis

Archeological and paleontological bone samples can potentially provide valuable information that can be forensically useful to future research and application. Proteins are robust and do not quickly degrade due to environmental conditions or outside factors. Therefore, understanding potential proteomic signatures in bone is useful when DNA may be too degraded to provide information about the subject. An analysis encompassing bone samples and gelatinous materials was conducted to determine similarities between the two matrices. Radiocarbon dates and ontogenetic ages also compared the samples to identify patterns between the samples. The samples underwent a reduction, alkylation, and trypsin digestion prior to instrumental analysis. The samples were analyzed with an Exploris 480 orbitrap mass spectrometer with an in-line Dionex Ultimate 3K UPLC. The most abundant proteins found in the samples consist of albumin (ALB) and collagen type I (COL1A1). A range of 52-749 peptides (mean 262) and 48-98 proteins (mean 49) were identified in bone samples. The gelatinous material samples identified more peptides with a range of 112 to 754 and an average of 415 peptides. The proteins identified in gelatinous materials range from 13 to 107 groups, averaging 57 proteins. The proteins were categorized into four different groups: blood/serum proteins, extracellular proteins, collagen proteins, and “other” proteins. The bone samples’ proteins were compared based on their ontogenetic age and radiocarbon date. The bone samples were categorized into four groups: Perinate/neonate, 15-23 years old, 24-40 years old, and 40+ in which 47, 37, 15, and 11 exclusive proteins were identified, respectively. The unique and exclusive identified proteins decreased as the ontogenetic age increased. The bone samples were organized into three groups based on their radiocarbon date: 500-1000, 1001-1100, and 1101-1600 years old. The first group (500-1000) identified 97 exclusive proteins. The second group (1001-1100) identified 30 exclusive proteins, and the oldest bones (1101-1600) identified eight exclusive proteins. The gelatinous material samples were compared based on their appearance and structure. The white and feather-like sample contained 31 exclusive proteins, whereas the brown and feather-like identified one protein. The oily and tacky samples identified two exclusive proteins. The paired gelatinous material and bone samples were compared and showed that collagen and albumin prefer the gelatinous material, and most extracellular matrix proteins are found in bone matrix. This paper demonstrates the variability of proteins in bone samples based on their ontogenetic and radiocarbon age. The presence of proteins in gelatinous material with varying physical appearance is also compared to identify potential proteins responsible for physical variability. Overall, the data shows potential gelatinous and bone proteomics use in forensic and bioarcheological spaces.