Stankiewicz B A, Hutchins J C, Thomson R, Briggs D E, Evershed R P
Department of Geology, University of Bristol, UK.
Rapid Commun Mass Spectrom. 1997;11(17):1884-90. doi: 10.1002/(SICI)1097-0231(199711)11:17<1884::AID-RCM62>3.0.CO;2-5.
Flash pyrolysis-gas chromatography/mass spectrometry (py-GC/MS) was used to assess the quality and mechanism of protein preservation in the tissue of Iron Age bog bodies from Lindow, UK, and south-eastern Drenthe, The Netherlands. Abundant pyrolysis products of the fresh skin tissue, including 2,5-diketopiperazines of Pro-Gly, Pro-Ala, Pro-Val, Pro-Pro and Hyp, were readily assigned to specific amino acid or dipeptide moieties. Comparison of the pyrolysates of the bog-body tissues with that of modern samples revealed qualitative similarities suggesting good preservation of the collagen and non-collagenous proteins in the ancient tissues. Examination of the pyrolysates of samples of fresh calf skin, which had been treated with various vegetable tanning agents, clearly revealed markers of non-hydrolysable tannins including 1,2-benzenediol, 1,3-benzenediol and 1,2,3-benzenetriol, although chromatographic quality inevitably diminished with increasing functionalization of the compounds. Such markers were not detected in the pyrolysates of the bog-body tissues. Instead 4-isopropenylphenol, a characteristic pyrolysis product of Sphagnum moss, was detected in both solvent-extracted and base-treated samples of tissue. The presence of 4-isopropenylphenol in the pyrolysates of the bog-body tissues provides evidence that their preservation involves reactions of amino acids with sphagnum acid, and possibly other agents derived from the peat. The study constitutes the first chemical characterization of the pyrolysis products of modern and ancient collagen.
采用快速热解-气相色谱/质谱联用技术（py-GC/MS）评估了来自英国林多和荷兰东南部德伦特省铁器时代泥炭沼尸体组织中蛋白质的保存质量及机制。新鲜皮肤组织的大量热解产物，包括脯氨酸-甘氨酸、脯氨酸-丙氨酸、脯氨酸-缬氨酸、脯氨酸-脯氨酸和羟脯氨酸的2,5-二酮哌嗪，很容易被归为特定的氨基酸或二肽部分。将泥炭沼尸体组织的热解产物与现代样本的热解产物进行比较，发现了定性上的相似性，这表明古代组织中的胶原蛋白和非胶原蛋白得到了良好的保存。对用各种植物鞣剂处理过的新鲜小牛皮皮肤样本的热解产物进行检测，清楚地发现了包括1,2-苯二酚、1,3-苯二酚和1,2,3-苯三酚在内的不可水解单宁的标记物，不过随着化合物功能化程度的增加，色谱质量不可避免地会下降。在泥炭沼尸体组织的热解产物中未检测到此类标记物。相反，在组织经溶剂萃取和碱处理的样本中均检测到了泥炭藓的特征性热解产物4-异丙烯基苯酚。泥炭沼尸体组织热解产物中4-异丙烯基苯酚的存在证明，其保存涉及氨基酸与泥炭藓酸以及可能来自泥炭的其他物质的反应。该研究首次对现代和古代胶原蛋白的热解产物进行了化学表征。
