Collagen indicator

Scariano, J. K., Glew, R. H., Bou-Serhal, C. E., Clemens, J. D., Garry, P. J., and Baumgartner, R. N., Serum levels of cross-linked N-telopeptides and aminoterminal propeptides of type I collagen indicate low bone mineral density in elderly women. Bone 23, 471—477 (1998). 

The presence of organic impurities in fossil as well as in the HCl-soluble fraction of modem bone collagen indicates that part of these non-collagen organics may be a component of bone, possibly carbohydrates. It is possible that upon fossilization under certain environmental conditions of burial, the relative amount of these materials increases independently of age. This may result from bacterial reworking of the bone organic matter. 

Chapman, W., Sherman, R., Boyce, S., Malawer, M., Hill, A., Buncke, G., Block, J., Fung, J., Clavien, R, Lee, K., Lebovic, G., Wren, S., Diethrich, E. and Goldstein, R., A novel collagen-based composite offers effective hemostasis for multiple surgical indications Results of a randomized controlled trial. Surgery, 129, 445-450 (2001). 

Table 5. Formation of the negatively and positive sequences in water and methanol, indicated by the collagen-like CD spectra and by the shape of the temperature transition curve...

Walker, PL. and DeNiro, M.J. 1986 Stable nitrogen and carbon isotope ratios in bone collagen as indices of prebistoric dietary dependence on marine and terrestrial resources in Soutbem California. American Journal of Physical Anthropology 71 51-61. 

Figure 9.3. Percentage of non-detectable amino acids in collagen extracts from archaeological human skeletons. Numbers on top of the columns indicate number of carbon atoms per amino acid. XW = weighted mean of % loss (cf. text). Only high-carbon amino acids are more frequently lost than the average.

The mean difference between collagen and flesh (A Nco.f) values for the first sacrificed pairs (91 days after birth) is 0.3 1.09%o while that for third pairs (171 days after birth) is 1.4 0.45%o. This result was unanticipated but seems robust. This indicates the relationship between diet and tissue 8 N and age is complex and varies between tissues. Future studies of diet-tissue nitrogen isotope spacing will have to consider age effects. This contrasts with carbon isotopes (Ambrose and Norr 1993), where we have observed little increase in 8 C with age in the same individuals. 

Carnivores rely on a protein-rich diet and produce new biomass primarily from dietary amino acids, although the enzymes required for de novo amino acid synthesis are present (Garmes et al., 1998). Bone collagen, muscle (meat) and apatite were analyzed for a set of modern southern African herbivores and carnivores (Lee-Thorp et al., 1989). The isotopic analyses showed i C enrichment in bone collagen, apatite and muscle, and depletion in lipids. Difference in values between herbivores and carnivores indicates a trophic effect, which for carbon in bone collagen is 2.5-3%o (Fig. 2). 

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