Protein stability in preserved biological remains

Paleoamerican exploitation of extinct megafauna revealed through immunological blood residue and microwear analysis, North and South Carolina, USA

Previous immunological studies in the eastern USA have failed to establish a direct connection between Paleoamericans and extinct megafauna species. The lack of physical evidence for the presence of extinct megafauna begs the question, did early Paleoamericans regularly hunt or scavenge these animals, or were some megafauna already extinct? In this study of 120 Paleoamerican stone tools from across North and South Carolina, we investigate this question using crossover immunoelectrophoresis (CIEP). We find immunological support for the exploitation of extant and extinct megafauna, including Proboscidea, Equidae, and Bovidae (possibly Bison antiquus), on Clovis points and scrapers, as well as possible early Paleoamerican Haw River points. Post-Clovis points tested positive for Equidae and Bovidae but not Proboscidea. Microwear results are consistent with projectile usage, butchery, fresh- and dry hide scraping, the use of ochre-coated dry hides for hafting, and dry hide sheath wear. This study represents the first direct evidence of the exploitation of extinct megafauna by Clovis and other Paleoamerican cultures in the Carolinas and more broadly, across the eastern United States, where there is generally poor to non-existent faunal preservation. Future CIEP analysis of stone tools may provide evidence on the timing and demography of megafaunal collapse leading to eventual extinction.

The use of crossover immunoelectrophoresis to detect human blood protein in soil from an ambush scene in Kosovo

This study examines the survivability of human blood proteins in soils from a year and a half old ambush scene in Kosovo. A total of 72 soil samples were collected, a number of which were directly associated with bone fragments or bullet projectiles. The samples were examined using crossover immunoelectrophoresis (CIEP) to determine the presence of blood protein and species affiliation. Human blood proteins were identified in 44 of the 72 samples (61%) with the majority of the positive observations (29 of 44) found 0.0-4.5 cm below ground surface (65%). Chi-squared and two-sample difference of proportions tests confirmed significant differences between samples with and without associated physical evidence and the presence and depth of human blood proteins. While DNA has largely replaced immunological analysis in forensic analyses, our results suggest that in particular situations, CIEP may still be a valuable tool in criminology.

Forensics on wild animals: differentiation between otter and pheasant blood using electrophoretic methods

Electrophoretic techniques were used to prove illegal hunting of a protected species as small amounts of dried blood stains could be clearly identified as of otter origin. Species differentiation between the otter (Lutra lutra) and pheasant (Phasianus colchicus) was based mainly on small differences in electrophoretic mobilities of the respective albumins and hemoglobins in one-dimensional separations. Additional differences in minor proteins of the two species were revealed by two-dimensional electrophoresis. Electrophoresis thus also proved to be a valuable tool for forensic purposes.

Detection of human proteins in buried blood using ELISA and monoclonal antibodies: towards the reliable species indentification of blood stains on buried material

The survival of human proteins in blood stains on fragments of cloth buried in exposed soil was examined in a 15-month investigation carried out from September 1990 to December 1991. During this period there was a wide variety of weather conditions. Samples were exhumed at 4-weekly intervals for 16 weeks and finally at 65 weeks; extracts of the stains were tested for albumin and IgG using a highly specific and sensitive enzyme-linked immunosorbent assay (ELISA) performed with monoclonal antibodies. Human albumin survived well throughout the 15 months of study, but IgG could be detected only in the 4- and 8-week samples. The reactions for IgG were weaker than those for albumin, although the method's sensitivity (10 ng) was the same for each protein. Appropriate buried and non-buried control experiments were carried out using cloth, either unstained or stained with human blood or animal sera; there was no cross-reactivity between human and the other species investigated and soil did not affect the assay; under laboratory conditions, IgG and albumin survived equally well. The system's versatility was illustrated by using monoclonal anti-bovine-albumin to detect specific albumin in the extracts of buried cloth which has been stained with bovine serum. It was concluded that ELISA performed with monoclonal antibodies could be of great value in identifying blood stains for forensic purposes.(ABSTRACT TRUNCATED AT 250 WORDS)

Molecular preservation

The differing patterns of molecular abundances in organisms are fundamental to the understanding of the biomolecular palaeontological record. All organisms contain DNA, RNA, protein, polysaccharides and lipid components, together with glycolipids, lipopolysaccharides and other complex molecules. Certain biopolymers, however, are restricted in their distributions; for example, lignin, cutin and sporopollenin are found only in terrestrial plants. The detailed chemical structures, namely the bond types present and their precise intramolecular environments, determine resistance to degradation. Observations of biomolecular preservation are compared with predictions based on chemical structure and on conditions encountered during decay.

Proteins and molecular palaeontology

Protein taxonomy has existed as a concept at least since 1958, but despite the efforts of the past 30 years, comparative studies of protein sequence, structure and distribution have not revolutionized any areas of systematics. The most interesting results of single gene phylogenies have been the anomalies, such as insulin in hystricomorphs or cytochrome c in the rattlesnake. It is likely that protein sequence information can be obtained in sufficient quality and quantity from ancient material as to change this finding? The paper will assess possibilities and the likely limitations of chemical studies of ancient protein material.

Mammoth albumin

Serum albumin was detected immunologically in muscle from a mammoth that died about 40,000 years ago. Rabbits injected with ground mammoth muscle produced antibodies that react strongly with elephant albumin, weakly with sea cow albumin, and still more weakly or not at all with other mammalian albumins. Since elephant albumin elicited antibodies with the same specificity, some of the surviving mammoth albumin molecules evidently have antigenic sites identical to those on native elephant albumin. Much of the mammoth albumin has, however, undergone postmortem change. The small amount of soluble albumin extractable from mammoth muscle is heterogeneous in size, charge, and antigenic properties.

Preservation of proteins in mummified tissues

Protein material was extracted from the dessicated tissues of several Egyptian mummies and a frozen Eskimo. The distribution and degree of preservation of high molecular weight protein was analyzed by gel filtration, protein assays, amino acid analysis, and polyacrylamide gel electrophoresis. The protein has undergone considerable degradation although some high molecular weight protein (C. 130,000 daltons) remains intact. Amino acid analysis of the extracted protein indicates the basic amino acids have undergone a chemical modification and may represent a point of preferential breakdown in the polypeptide chain. Atomic absorption spectrophotometry of tissue cations suggests a correlation between degree of preservation of mummified tissue and levels of sodium salts (natron) in the tissue.