Using MS to identify dinosaur fossils proteins

Scientists from North Carolina State and Harvard Universities, along with John M Asara PhD, director of the mass spectrometry core facility at the Beth Israel Deaconess Medical Center (BIDMC), a teaching hospital of Harvard Medical School, have used a Thermo Scientific LTQ linear ion trap and LTQ Orbitrap XL to extract and sequence tiny pieces of collagen protein from dinosaurs. The sequences from a 68 million-year-old Tyrannosaurus Rex and a 160,000- to 600,000-year-old mastodon are the oldest to ever be reported.

The protein fragments were compared to peptide/protein sequences in existing databases, leading the researchers to propose a link between the T. rex and current-day chickens and the mastodon with modern elephants. Recently, the Harvard team has been able to place the T. rex on the animal kingdom's phylogenetic tree using molecular evidence.

The mass spectrometry techniques John Asara has developed for sequencing proteins in human tumours using the LTQ linear ion trap and LTQ Orbitrap XL have been applicable to his work on fossilomics (the analysis of fossil bone proteins from extinct organisms).

The team uses mass spectrometry to develop proteomics-based strategies for identifying novel signalling proteins and modifications of functional significance to cancer pathways.

Asara credits the Thermo Scientific instrumentation with providing the sensitivity, ultra-high mass accuracy and resolution required by these challenging applications. "The LTQ increased our throughput and depth of analyses," Asara said. "Additionally, the LTQ Orbitrap XL has done wonders for sorting out minor sequence discrepancies. With the LTQ Orbitrap XL, all forms of proteomics analysis are possible from qualitative analysis to quantitative analysis through stable isotope labelling, as well as label-free methods."

Both Asara's cancer research and fossilomics analyses benefit from the advanced Thermo Scientific MS technology. "The two technological advances that stand out with my current instrumentation are the linear trap with dual ejection to two different multipliers, which substantially increases sensitivity and scan speed, as well as the Orbitrap's capability for high-resolution accurate mass measurements," Asara said. "Additionally, the HCD collision cell on the LTQ Orbitrap XL allows for extremely high MS/MS mass accuracy and resolution, in addition to acquiring very low molecular weight fragment ions."

For more information visit www.fossilomics.com.