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Shortly after Max Planck shook the scientific world with ideas about the fundamental quantization of energy, researchers built and leveraged theories of quantum mechanics to resolve physical phenomena that had previously been unexplainable, including the behavior of heat in solids and light absorption on an atomic level. In the 120-plus years since, researchers have looked beyond physics and used quantum theory’s same perplexing — even “,” according to Einstein — laws to solve inexplicable phenomena in a variety of other disciplines.

Today, researchers at the ����ֱ�� Applied Physics Laboratory (APL) in Laurel, Maryland, are applying quantum mechanics to biology to better understand one of nature’s biggest mysteries — magnetosensitivity, an organism’s ability to sense Earth’s magnetic field and use it as a tool to adjust some biological processes. And they’ve found some surprising results.

In a recent study, APL research engineer and scientist Carlos Martino and his APL colleagues Nam Le, Michael Salerno, Janna Domenico, Christopher Stiles, Megan Hannegan, and Ryan McQuillen, along with Ilia Solov’yov from the Carl von Ossietzky University of Oldenburg in Germany, that an enzyme that plays a central role in human metabolism has some of the same key features as a magnetically sensitive protein found in birds.

“This research is game changing,” said Martino. “For the first time ever, we’ve opened up the possibility that an external magnetic field could have an influence on the underlying chemistry of a protein found in humans.”

The human protein look-alike is the electron transfer flavoprotein (ETF), a well-known enzyme in mitochondria that is responsible for transferring electrons to generate the energy that keeps us alive. ETF isn’t known to be magnetically sensitive in humans, but its structure and oxygen-binding behavior are remarkably similar to certain cryptochrome proteins that are known to be magnetosensitive in other species like birds.

And as the team found out, the way that ETF interacts with oxygen to produce reactive oxygen species (ROS) could be very similar to the interactions studied in the proteins of migratory birds.

“That means ROS are our target for the magnetically sensitive effect,” said Domenico, a computational chemist in APL’s Research and Exploratory Development Department. “So by understanding how ROS is generated inside the enzyme, we can theoretically control its magnetic field response.”

That turned out to be easier said than done. Although Hannegan and McQuillen could experimentally measure the levels of ROS formed by ETF, it’s impossible to see where the reactive species are forming within the enzyme.

“There is no way to look at or get inside the proteins to see what’s happening,” said Le.

Enter computational modeling. By running molecular dynamic simulations using millions of CPU-hours to model oxygen diffusion in ETF enzymes, the team was able to isolate where oxygen most likely binds to ETF and in turn discover several high-probability locations where ROS were likely being made.

“From there, we can go back and possibly change the ETF into something that’s engineered and see how we’re able to increase or decrease the output of those reactions,” Domenico said. Doing so could give researchers the ability to modulate the extent of the magnetic field response of this protein inside of a person’s cells.

“This is really new and revolutionary research, not just at APL, but in the scientific community at large,” said Sarah Herman, APL’s Biological and Chemical Sciences program manager. “We don’t know for certain what the specific applications for this could be in the future, but if you were to sit and explore possibilities, you might begin to wonder how brain cells that are magnetically sensitive would respond to a different magnetic field on the Moon, or perhaps on Mars.”