Collagen fractionation

Figure 10.2. Schematic diagram showing how restricted conversion of fatty acids to amino acids influences the fractionation between collagen and CO3 of bone apatite LI = lipid component, PR = protein, T = total isotopic composition AP = COj component of apatite, a) Herbivorous diet (Cj plants only) b) Carnivorous diet, assuming rj = 1 (no barrier to fatty acid conversion to AAs) c) Carnivorous diet, assuming ri < 1 note that carbonate-collagen fractionation is smaller.

Los Angeles. The 14C values on "Los Angeles Man" was >23,600 (UCLA-1430) 14C years [16,17]. On the other hand, 14C determinations on the collagen fraction of two skeletal samples from South America have resulted in a significant reduction in their previously... 

The bomb pulse method is now considered to be one of the most useful techniques for distinguishing between modern and ancient remains (Geyh 2001 Ubelaker, Buccholz, and Stewart 2006 Wild et al. 1998). Attempts to improve the accuracy of the technique have demonstrated the importance of analyzing a bone fraction that contains a rapid turnover rate (Wild et al. 1998). Analysis of the collagen fraction of recent bone has been shown to be less accurate as a result of its relatively long carbon turnover rate compared with other bone fractions (Ubelaker 2001). Lipids from bone and bone... 

The small amount of organic impurities coexisting with the separated collagen from Folsom bison and whale bone indicates that the method used is successful in these two cases. Both of the collagen fractions, HCl-insoluble and HCl-soluble, are pure and could be used safely for radiocarbon dating. This is reflected by the good agreement between the... 

Another aspect of this study is the racemization of the amino acid residues in the separated collagen fractions (15). Contamination is often cited if the extent of racemization is lower than expected. We have found that the non-collagen fraction is often more highly racemized than is the... 

In humans, the meat protein of the diet usually controls the isotopic composition of bone collagen, while carbohydrates from plant foods usually control the isotopic composition of apatite Our models indicate that reconstruction of diets from isotopic analyses of bone cannot be accomplished solely by the use of the collagen fraction The use of both collagen and hydroxyapatite phases of bone allows differentiation between energy and growth components of the diet, and therefore gives a considerable amount of detailed information about the total diet ... 

Figure 4.7 (a) The isovolumetric collagen fraction In bovine cortical bone is shown in the center, and maps of stress stored in the apatite crystals within this area are shown at the side. The values on each individual stress map Indicate the remote uniaxial stress field... 

A collagen fraction from the body wall glycoproteins of the leech, Hirudo medicinalis, has been shown to contain a higher proportion of D-glucosyl-o-galactosyl-L-hydroxylysine units than other vertebrate and invertebrate collagens. ... 

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