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past feature
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Bone Reveals 55,000
Year Old Protein
Mass
spectrometry has been used to identify the
protein osteocalcin from a bone of an
ancient Bison in Siberia. For the first
time, Christina Nielsen-Marsh, of
Newcastle University, and colleagues at
the University of Oxford, Harvard
University, and Michigan State University
have managed to retrieve an intact protein
from a fossil bone more than 55,000 years
old.
The molecules were extracted from extinct
bison remains located in the permafrost in
Siberia, Russia. The protein is important
in bone formation.
The protein was ionized from the sample
using matrix-assisted laser desorption
ionization mass spectrometry (MALDI-MS)
and sequenced at Michigan State University
. Remarkably, the primary sequence of the
protein was recovered intact, including
the relatively unstable carboxylated
glutamic acid (gamma-carboxy glutamic
acid) residues. The researchers
demonstrate that osteocalcin can survive
in bones even heated to temperatures of
165C for several hours.
"This research is groundbreaking" says
Nielsen-Marsh, "because it finally puts to
rest the question of whether intact
proteins can exist in fossilized bones".
"Moreover, intriguing data from our
laboratories suggest that extending
protein sequencing well beyond 55,000
years is a realistic possibility."
The results of the study appear in the
December issue of the journal
Geology.
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