A twist in the tale of dinosaur proteins

By Ed Yong | June 14, 2011 6:15 pm

I have a piece in Nature News about the controversial claim that Mary Schweitzer has recovered proteins from the fossilised bones of two dinosaurs – Tyrannosaurus and Brachylophosaurus. These samples are 68 and 80 million years old respectively, and the discovery of proteins that ancient has been met by excited awe from some scientists and aggressive criticism from others.

Evan Ratliff wrote a fantastic piece about the debate circa mid-2009, and I blogged about the Brachylophosarus discovery that cropped up since. The new paper is an important part of the story because it addresses one of the biggest source of contention – the implausibility of proteins surviving for tens of millions of years. Here’s an excerpt, but do read the full thing:

Scientists have discovered how fragments of the protein collagen might have survived in fossilized dinosaur bones. The intertwining, rope-like structure of the molecule, a major component of bone, could have shielded parts of the protein from enzymes and the elements for tens of millions of years, they say.

The results, which are published in PLoS ONE, support the contentious claim that dinosaur proteins have been recovered and sequenced.

Collagen molecules consist of three long protein subunits that coil around each other in a triple helix. Five of these helices wind together to make up a microfibril, and thousands of microfibrils gather to form a fibril.

“It’s like a massive, multi-stranded rope,” says James San Antonio, lead author of the paper and a biochemist at Orthovita, a medical-implant manufacturer in Malvern, Philadelphia.

San Antonio’s team compared the recovered collagen fragments with models of human and rat collagen, and found that all 11 pieces came from the innermost parts of the microfibrils. Some originated in the same location in both dinosaurs. The researchers say that sites deep inside the collagen fibre would have been shielded from degrading enzymes and the environment.

CATEGORIZED UNDER: Dinosaurs, Palaeontology

Comments (4)

  1. Robert S-R

    Schweitzer’s been in the news before, has she not? She had supposedly found soft tissue in fossilized bone, if I recall.

    Edit: I just looked it up to confirm it, and my memory served me well. Now why can’t I keep straight the names of people I actually know?

  2. Noumenon

    That article had a lot of really good paragraphs that just weren’t in the original articles about this debate. The only thing I’d like to know is about the sentence “Theoretical predictions and lab experiments suggest that proteins cannot survive for more than a few million years.” I could have used a parenthetical like “a few million years (because of eventual decay in their hydrogen bonds)” because I have no idea what the limiting factor is. If you told me proteins can’t survive for more than 10000 years I’d say “OK, I believe you.”

  3. An fascinating dialogue is price comment. I think that you must write more on this subject, it won’t be a taboo subject but generally persons are not sufficient to talk on such topics. To the next. Cheers

  4. As a part time sports lover and a part-time Paleontologist I find this post very interesting. However, I too find it very, very difficult to believe the ” plausibility of proteins surviving for tens of millions of years.” How could it be? I hear the researcher explanation but I’m somewhat lost to believe it “tens of millions”. All the same I found this reading captivating and research the resources kept me busy for hours. Kind Regards


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