A role for iron and oxygen chemistry in preserving soft tissues, cells and molecules from deep time

作者：Schweitzer Mary H^*; Zheng Wenxia; Cleland Timothy P; Goodwin Mark B; Boatman Elizabeth; Theil Elizabeth; Marcus Matthew A; Fakra Sirine C

来源：Proceedings of the Royal Society B, 2014, 281(1775): 20132741.

DOI：10.1098/rspb.2013.2741

• soft tissue preservation
• haemoglobin
• iron
• goethite
• Fenton chemistry
• protein cross-linking

The persistence of original soft tissues in Mesozoic fossil bone is not explained by current chemical degradation models. We identified iron particles (goethite-alpha FeO(OH)) associated with soft tissues recovered from two Mesozoic dinosaurs, using transmission electron microscopy, electron energy loss spectroscopy, micro-X-ray diffraction and Fe micro-X-ray absorption near-edge structure. Iron chelators increased fossil tissue immunoreactivity to multiple antibodies dramatically, suggesting a role for iron in both preserving and masking proteins in fossil tissues. Haemoglobin (HB) increased tissue stability more than 200-fold, from approximately 3 days to more than two years at room temperature (25 degrees C) in an ostrich blood vessel model developed to test post-mortem 'tissue fixation' by cross-linking or peroxidation. HB-induced solution hypoxia coupled with iron chelation enhances preservation as follows: HB + O-2 > HB - O-2 > -O-2 >> +O-2. The well-known O-2/haeme interactions in the chemistry of life, such as respiration and bioenergetics, are complemented by O-2/haeme interactions in the preservation of fossil soft tissues.

• 出版日期2014-1-22