The fossil of an extinct giant beaver species — unearthed 170 years ago in New York — offers new insights into paleoproteomics, the study of ancient proteins.
Ancient proteins are potentially useful in positioning animals on the evolutionary tree as well as in understanding the evolution of life and the planet over time.
Researchers who study ancient proteins would depend on fossils dug up for the specific purpose. In the new study, the team used a fossilized giant beaver skull obtained in 1845 from Central New York and has been housed since then at New York State Museum.
"In paleoproteomics we've generally looked at specimens collected recently and carefully stored in climate-controlled conditions,” explained study author and postdoc researcher Timothy Cleland from the University of Texas-Austin, adding that in their study they dealt with a specimen long sitting on a museum shelf.
That is the challenge when using existing fossils for paleoproteomics, a young discipline: will the long gathered specimens offer the needed protein information?
For this study, the team extracted proteins coming from the Castoroides ohioensis skull, the first ever found, and used a technique called mass spectrometry analysis to seek for proteins, which are amino acid chains obtained from instructions in DNA that assume a number of roles in living organisms.
They detected plenty of specimens of collagen 1, the most prevalent bone protein, along with post-translational modifications or chemical changes found on the protein surface that are not DNA-defined. Discovering these modifications is considered valuable since it has little precedent in the emerging field.
Cleland said, for instance, that post-translational modifications of some proteins can shed light on how certain organisms manipulate or process the protein, such as collagen, for better functioning. What has been done so far is just “scratching the surface,” noted the authors.
A database containing post-translational modifications to ancient creatures, as well as a database of primary protein sequences, is hoped to be used for better tackling evolutionary changes. Protein engineering, too, can see how an ancient protein function compares to the same in modern living animals.
The research also emphasized the significance of museum collections in further research and scientific exploration.
“Without maintaining collections rich in diversity of specimens, both ancient and modern, similar research that examines these windows into our past would not be possible,” said vertebrate paleontology curator Robert Feranec of New York State Museum.
The findings were detailed in the journal Proceedings of the Royal Society B.