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Author Topic:   Dinosaur blood?
Dr_Tazimus_maximus
Member (Idle past 3245 days)
Posts: 402
From: Gaithersburg, MD, USA
Joined: 03-19-2002


Message 9 of 22 (117938)
06-23-2004 3:01 PM
Reply to: Message 8 by Mammuthus
06-23-2004 4:18 AM


Re: Read a bit more carefully
Hi Mammuthus,
Actually I think that the evidence for the protein degradation products is pretty strong. The leg bones were capped (I believe that is the correct word for when the ends of a long bone fossilizes) maintaining the integrity of the interior portion. Also the presence of the calcium phosphate matrix has a tendency to stabilize proteins, essentially it is a hydroxyapatite matrix which is known to bind proteins, dome with a very high affinity. The protein was old enough for recemization to have occurred, a process that was probably slowed by the binding of the degradation products to the mineral matrix, check this out for a small amount of supporting data for stability.
As mentioned above, there have been a number of reports concerning the preservation of osteocalcin indicated both by fragments capable of generating an immune response and the presence of remnants of the modified amino acid g-carboxyglutamic acid.One of the references is Preservation of the Bone Protein Osteocalcin in Dinosaurs Geology, Vol. 20, October 1992, pages 871-874. I will try to find a couple of the other ones that I have at home.
While not much is required in the way of the linear epitopes required for the generation antibodies, the racemization actually may have increased the immunogenicity. I do not have much info in that regard, but the lack of a reaction from the surrounding tissues and samples is indicative that the results were real.

"Chance favors the prepared mind." L. Pasteur
and my family motto
Transfixus sed non mortis
Taz

This message is a reply to:
 Message 8 by Mammuthus, posted 06-23-2004 4:18 AM Mammuthus has not replied

  
Dr_Tazimus_maximus
Member (Idle past 3245 days)
Posts: 402
From: Gaithersburg, MD, USA
Joined: 03-19-2002


Message 11 of 22 (118087)
06-23-2004 11:44 PM
Reply to: Message 10 by Loudmouth
06-23-2004 4:24 PM


Hi Loudmouth, I actually have had a reprint of the paper since shortly after it came out. . What interests me the most is the relationship between the tissue where the degraded proteins are found and the chemistry of stabilization. I have been using hydroxyapatite for years as a purification matrix and have found that it can also be used to bind protiens and hold them in a stable form in a liquid formulation much longer than can normally be expected in a standard liquid formulation. Activity and structure are often held stable over substantial periods (substantial for a protein biologic anyway). As part of my work currently revolves around determining the stability of my biologics this was obviously of a great deal of interest to me. It was not until I read about this and other bone proteins from fossils that I started to consider other implacations, re: protein fragments from fossils.
This message has been edited by Dr_Tazimus_maximus, 06-23-2004 10:46 PM

"Chance favors the prepared mind." L. Pasteur
and my family motto
Transfixus sed non mortis
Taz

This message is a reply to:
 Message 10 by Loudmouth, posted 06-23-2004 4:24 PM Loudmouth has replied

Replies to this message:
 Message 12 by Mammuthus, posted 06-24-2004 4:23 AM Dr_Tazimus_maximus has not replied
 Message 13 by Loudmouth, posted 06-24-2004 12:18 PM Dr_Tazimus_maximus has not replied

  
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