In-depth research conducted at MIT might just have unraveled a long-standing mystery surrounding the preservation of dinosaur collagen. This protein, crucial for bone and tissue structure, has been found intact in fossils dating back as far as 195 million years, lingering long beyond its expected peptide bond half-life of around 500 years. Scientists now suggest a unique atomic interaction may shield these ancient bonds from the typical hydrolytic demise.
The study, led by MIT postdoc Jinyi Yang Ph.D. '24 and overseen by Ron Raines, the Firmenich Professor of Chemistry, points to an atomic guard that effectively blocks water molecules from cleaving the peptide bonds. "We provide evidence that that interaction prevents water from attacking the peptide bonds and cleaving them," Ron Raines told MIT News. This defensive mechanism seems to defy the typical vulnerabilities of standard peptide bonds, known to degrade within mere centuries.
The MIT team, which also included Volga Kojasoy and Gerard Porter, clarified the role of electron pairs in neighboring peptide bonds which protectively combine to create a barrier against water. By analyzing two types of collagen mimics, one stable in water and the other susceptible to hydrolysis, they provided clear evidence of the structural resilience in the natural state of collagen.
In explaining the significance of these findings, Paramjit Arora, a professor of chemistry at New York University and not involved in the research, emphasized the importance of this discovery. “The paper directly addresses the remarkable finding of intact collagen in the ribs of a 195-million-old dinosaur fossil, and shows that overlap of filled and empty orbitals controls the conformational and hydrolytic stability of collagen,” Arora explained to MIT News.
Raines further differentiated the robust structure of collagen, which consists entirely of triple helices, from other protein structures that contain potentially vulnerable links. "Collagen is all triple helices, from one end to the other," he said. "There’s no weak link, and that’s why I think it has survived." While acknowledging other factors may contribute, Raines believes the molecular and atomic-level phenomena are key to collagen’s remarkable longevity, according to MIT News.
Supported by funding from the National Institutes of Health and the National Science Foundation, this groundbreaking work sheds light on a profound biochemical conundrum, perhaps closing the chapter on why certain dinosaur relics have withstood the test of time far beyond initial scientific expectations.
