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Author Topic:   Dinosaur blood?
Loudmouth
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Message 10 of 22 (117975)
06-23-2004 4:24 PM


For those interested, here is the abstract and link to the actual primary literature on the find:
Abstract:
Proc Natl Acad Sci U S A. 1997 Jun 10;94(12):6291-6.
Heme compounds in dinosaur trabecular bone.
Schweitzer MH, Marshall M, Carron K, Bohle DS, Busse SC, Arnold EV, Barnard D, Horner JR, Starkey JR.
Department of Biology and Museum of the Rockies, Montana State University, Bozeman, MT 59717, USA.
Six independent lines of evidence point to the existence of heme-containing compounds and/or hemoglobin breakdown products in extracts of trabecular tissues of the large theropod dinosaur Tyrannosaurus rex. These include signatures from nuclear magnetic resonance and electron spin resonance that indicate the presence of a paramagnetic compound consistent with heme. In addition, UV/visible spectroscopy and high performance liquid chromatography data are consistent with the Soret absorbance characteristic of this molecule. Resonance Raman profiles are also consistent with a modified heme structure. Finally, when dinosaurian tissues were extracted for protein fragments and were used to immunize rats, the resulting antisera reacted positively with purified avian and mammalian hemoglobins. The most parsimonious explanation of this evidence is the presence of blood-derived hemoglobin compounds preserved in the dinosaurian tissues.
And here is the link to the free PNAS paper.
It would seem to me that they did indeed find heme. But like other discussions on ancient protein/DNA, contamination is a real possibility. However, they did control for it.
"Significant levels of D-enantiomers of individual amino acids (39) suggest that the source proteins are ancient. Considering the rapid burial and geological sequestration of the skeleton, as well as excellent microstructural preservation (39), the most likely source of these proteins is the once-living cells of the dinosaur. This is supported by the lack of signal from either embedding sandstone or plant material extracted in the same manner as the bone tissues in various analytical examinations."
This message has been edited by Loudmouth, 06-23-2004 03:25 PM

Replies to this message:
 Message 11 by Dr_Tazimus_maximus, posted 06-23-2004 11:44 PM Loudmouth has replied

  
Loudmouth
Inactive Member


Message 13 of 22 (118251)
06-24-2004 12:18 PM
Reply to: Message 11 by Dr_Tazimus_maximus
06-23-2004 11:44 PM


Hi Taz,
I too use hydroxyapatite for purification, but I have never considered using it for protein stabilization over extended periods. HPT has sort of lost favor over the years, but I love the stuff. Instead of a simple anion/cation exchange group it uses a complex crystal structure which contains both positive and negative groups. It's great for separating proteins of similar pI that have previously undergone separation under isoelectric focusing or simple anion/cation exchange. I am lucky enough to be able to freeze back my proteins in a 20% glycerol solution, but thanks for the info anyway.

This message is a reply to:
 Message 11 by Dr_Tazimus_maximus, posted 06-23-2004 11:44 PM Dr_Tazimus_maximus has not replied

  
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