MIT chemists offer a new explanation for how collagen in dinosaur bones may have survived millions of years: An atomic-level interaction prevents its bonds from being broken down by water.
Collagen, a protein found in bones and connective tissue, has been found in dinosaur fossils as old as 195 million years. That far exceeds the normal half-life of the peptide bonds that hold proteins together, which is about 500 years. A new study from MIT offers an explanation for how collagen can survive for so much longer than expected. The research team found that a special atomic-level interaction defends collagen from attack by water molecules. This barricade prevents water from breaking the peptide bonds through a process called hydrolysis. "We provide evidence that that interaction prevents water from attacking the peptide bonds and cleaving them. That just flies in the face of what happens with a normal peptide bond, which has a half-life of only 500 years," says Ron Raines, the Firmenich Professor of Chemistry at MIT. Raines is the senior author of the new study, which appears today in ACS Central Science. MIT postdoc Jinyi Yang PhD '24 is the lead author of the paper. MIT postdoc Volga Kojasoy and graduate student Gerard Porter are also authors of the study. Water-resistant Collagen is the most abundant protein in animals, and it is found in not only bones but also skin, muscles, and ligaments. It's made from long strands of protein that intertwine to form a tough triple helix. "Collagen is the scaffold that holds us together," Raines says. "What makes the collagen protein so stable, and such a good choice for this scaffold, is that unlike most proteins, it's fibrous." In the past decade, paleobiologists have found evidence of…