Using advanced computer simulations, scientists from Surrey’s Leverhulme Quantum Biology Doctoral Training Centre determined the role of proton tunneling in spontaneous mutations inside DNA.
Proton tunneling is a type of quantum tunneling involving the instantaneous disappearance of a proton in one site and the same proton’s appearance at an adjacent site separated by a potential barrier.
Scientists found that hydrogen bonds hold the two strands of the DNA‘s double helix together. Under certain circumstances, the hydrogen bonds can behave like spread-out waves that can exist in multiple locations at once, because of proton tunneling. This prompts these atoms to occasionally being found on the wrong strand of DNA, prompting mutations.
Despite having a short lifetime, these mutations can survive the DNA replication mechanism inside cells.
Dr. Marco Sacchi, the project lead and Royal Society University Research Fellow at the University of Surrey, said: “Many have long suspected that the quantum world—which is weird, counter-intuitive and wonderful—plays a role in life as we know it. While the idea that something can be present in two places at the same time might be absurd to many of us, this happens all the time in the quantum world, and our study confirms that quantum tunneling also happens in DNA at room temperature.”
Louie Slocombe, a Ph.D. student at the Leverhulme Quantum Biology Doctoral Training Centre and co-author of the study, said:
“There is still a long and exciting road ahead of us to understand how biological processes work on the subatomic level, but our study—and countless others over the recent years—have confirmed quantum mechanics are at play. In the future, we are hoping to investigate how tautomers produced by quantum tunneling can propagate and generate genetic mutations.”
- L. Slocombe et al. Quantum and classical effects in DNA point mutations: Watson–Crick tautomerism in AT and GC base pairs, Physical Chemistry Chemical Physics (2021). DOI: 10.1039/D0CP05781A