Many biologists assume that bizarre quantum phenomena play a relatively negligible role inside the cell. A recent theoretical analysis of the chemical

Quantum Tunneling Makes DNA More Unstable

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2022-09-21 15:00:28

Many biologists assume that bizarre quantum phenomena play a relatively negligible role inside the cell. A recent theoretical analysis of the chemical bonds holding DNA together, however, suggests that these effects might occur far more frequently than once thought—and act as a major source of genetic mutations.

Researchers led by Louie Slocombe of the University of Surrey in England focused on the molecular “bases” that make up the rungs linking DNA's double strands and the hydrogen bond, formed with a proton, that holds the two sides of these rungs together. Their theoretical model incorporated the quantum effects that allow a proton, bound to the base cytosine on one strand, to spontaneously “tunnel” and hook up to the guanine base on the other.

Such an altered base pair, known as a tautomer, can quickly jump back to its original arrangement. But if the proton does not make it back by the time the two DNA strands separate—the first step of DNA replication—the cytosine might bind to a different base, adenine, rather than guanine. This unnatural pairing creates a mutation.