Analysis collagen

Stable isotope analyses of the organic fraction of bone and of food samples was carried out on a Micromass Prism Mass Spectrometer in the Stable Isotope Laboratory, Department of Physics, University of Calgary, under the direction of H.R. Krouse. Collagen samples were combusted in a Carlo Erba gas analyser which provides information on the carbon and nitrogen content of the samples andintroduces Nior CO gases into the mass spectrometer for analysis of nitrogen or carbon stable isotopes, respectively. 

The diet of the 19 century residents of Upper Canada was determined from historical sources and was reproduced in order to carry out chemical analysis. Stable carbon isotope analysis of food and human bone demonstrates that the spacing between the food eaten and the bone collagen is around 5.6%o. The value may vary slightly from this estimate since the latter is based on a reconstructed diet and a large number of bone samples, which exhibit a small amount of variation. Nevertheless, this empirically derived result agrees well with estimates from field (Vogel 1978), and laboratory studies (reviewed in Ambrose 1993). 

Tykot, R.H., van der Merwe, N.J. and Hammond, N. 1996 Stable isotope analysis of bone collagen, bone apatite, and tooth enamel in the reconstruction of human diet. A case study from Cuello, Belize. In Orna, M.V., ed., Archaeological Chemistry Organic, Inorganic, and Biochemical Analysis. ACS Symposium Series 625, Washington, DC, American Chemical Society 355-365. 

Van Klinken, GJ. 1991 Dating and Dietary Reconstruction by Isotopic Analysis of Amino Acids in Fossil Bone Collagen—with Special Reference to the Caribbean. Ph.D. dissertation. University of Groningen, The Netherlands. 

Ambrose, S.H. 1990 Preparation and characterization of bone and tooth collagen for isotopic analysis. Journal of Archaeological Science 17 431 51. 

Fairgrieve, S.I. 1993 Amino acid residue analysis of Type I collagen in human hard tissue an assessment of cribra orbitalia in an ancient skeletal samplefrom tomb 31, site 31/435-D5-2, Dakhleh Oasis, Egypt. Ph.D. dissertation, University of Toronto. 

Liden, K., Takahasi, C. and Nelson, D.E. 1995 The effects of lipids in stable carbon isotope analysis and the effects of NaOH treatment on the composition of extracted bone collagen. Journal ofArchaeological Science 22 321-326. 

Since it is possible to differentiate well-preserved from badly preserved collagen through amino acid analysis and gel electrophoresis, it is also possible to determine which bone samples are likely to give erroneous isotopic ratios. At least for 8 C, it should be possible to estimate the in vivo isotopic signature by correcting the changed amino acid concentrations of the collagen extract. This way, a reasonable approach to the reconstruction of pale-odiet should be possible. 

NOTE ADDED IN PROOF This manuscript had been submitted shortly after the presentation of the paper at the Fourth Advanced Seminar on Pale-odiet, 1994. Ongoing research, especially stable isotope analysis of single amino acids from inoculated and non-inoculated marten bones (same specimens as in this paper) further and strongly support our conclusion that bacterial modifica-tion causes substantial shifts in collagen stable isotope ratios (Balzer et fl/. 1997). 

Paleodiet studies have focused on the analysis of collagen, due to its ability to survive in ancient bone. Like all proteins, collagen is composed of amino acid (AA) units present in relatively constant proportions characteristic of the specific protein. The isotopic composition of a sample of collagen is the weighted average of the 5 C values of each of the constituent amino acids. 

The prediction for carbonate is made for dpRo-cARs and dNONPRo-cARB = 11. and fOpHo-cARB = f()NONPRo-cARB = 1- The results, presented in the main body of this paper (Table 11.1), show close agreement between observed and predicted carbonate and collagen values. While the justification for the values used in the DIFF is not based on rigorous or systematic analysis of the data, it is adequate to demonstrate the general features, and to suggest that the values obtained be confirmed by further experiment. 

Balzer, A., Gleixner, G., Grupe, G., Schmidt, H.-L., Schramm, S., Turban-Just, S. (1997). In vitro decomposition of bone collagen by soil bacteria the implications for stable isotope analysis in archaeometry. Archaeometry 39 (2), 415-429. 

M. Collagen-based stmctures containing the peptoid residue N-isobutylglycine (Jtdeu). 6. Conformational analysis of Gly-Pro-Nleu sequences by NMR,... 

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