The coronovirus may be new, but nature long ago gave humans the tools to detect it, at least on a microscopic scale: antibodies, Y-shaped immune proteins that can latch onto pathogens and cause them to infiltrate cells. Can be blocked from.
Millions of years of development have honored these proteins in the disease fighting weapons they are today. But in a span of just a few months, a combination of human and machine intelligence overtook Mother Nature in its own game.
Using computational tools, a team of researchers at the University of Washington designed and built a molecule from scratch that, when stacked against the coronavirus in the lab, can attack as at least one antibody. When the nose of mice and hamster is pierced, it also appears to protect animals from becoming seriously ill.
This molecule, called a mini-binder for its ability to shine on coronoviruses, is sufficient and stable to engage sufficiently in a steady-dry state. Bacteria can also be engineered to churn these mini-binders, potentially making them not only effective, but also inexpensive and convenient.
The team’s product is still in the initial stage of development, and will not be on the market anytime soon. But so far “it looks very promising,” said Lauren Carter, one of the researchers behind the project, led by biochemist David Baker. Eventually, healthy people may be able to self-administer mini-binders in the form of a nasal spray, and potentially keep any inbound coronavirus particles at bay.
Dr. “The most beautiful application can be something that you place on your bedside table,” Carter said. “It’s like a dream.”
Mini-binders are not antibodies, but they spout the virus in roughly the same way. The coronovirus enters a cell using a kind of lock-and-key interaction, in which a protein called spike – key – is molded into a molecular lock called ACE-2, the outermost of some human cells. Decorates the part. Antibodies made by the human immune system can interfere with this process.
Many scientists are hopeful that mass-produced mimics of these antibodies can help prevent people from getting sick from being treated with Kovid-19 or getting infected. But to control the coronovirus, a lot of antibodies are required, especially if an infection is ongoing. Antibodies are also fantastic for producing and distributing to people.
To develop a less granular alternative, members of the Baker Lab, led by biochemist Longxing Cao, adopted a computational approach. The researchers described how millions of imaginary, lab-designed proteins would interact with Spike. After sequentially taking out the worst performers, the team selected the best among the bunches and synthesized them in the laboratory. They spent weeks toggling between computers and benches, flirting with simulations and designs to match reality.
The result was a fully homemade mini-binder that easily pasted itself from the virus, the team Reported in science last month.
“It goes a step further than the manufacture of natural proteins,” said Ashar Williams, a chemical engineer at Cornell University who was not involved in the research. If adapted for other purposes, Dr. Williams said, “It would be a big win for bioinformatics.”
Dr. Baker said the team is now working with deep-learning algorithms that can teach lab computers to streamline the iterative trial and error process of protein design in weeks rather than months.
But the novelty of the mini-binder approach can also be a drawback. For example, it is possible that the coronavirus mutates and becomes resistant to the DIY molecule.
Daniel-Adriano Silva, a biochemist at Seattle-based biopharmaceutical company Neolukin, formerly a Dr. at the University of Washington. Those trained with Baker can come up with another strategy that can solve the problem of resistance.
His team has also designed a protein that can block viruses from invading cells, but their DIY molecule is slightly more familiar. It is a smaller, stronger version of the human protein ACE-2 – one that has a very strong grip on the virus, so the molecule can potentially serve as a decay that keeps pathogens away from vulnerable cells.
Developing resistance would be futile, said Christopher Barnes, a structural biologist at the California Institute of Technology who partnered with Neolukin on his project. A coronavirus virus that could no longer bind to caries would probably lose the ability to bind to the real thing, the human version of ACE-2. “It’s a huge fitness cost for the virus,” Dr. Barnes said.
Both the mini-binder and the ACE-2 decoy are easier to make, and are likely to spend just as much money on the dollar than synthetic antibodies, which can Carry the price tag in the high thousands of dollars, Dr. Carter said. And while antibodies must be kept cool to maintain longevity, DIY proteins can be engineered to cure at room temperature, or even in more extreme conditions. University of Washington’s mini binder “can be boiled and it’s still fine,” Dr. Cao said.
This durability makes these molecules easier to transport, and easier to administer in various ways, perhaps by injecting them into the bloodstream as a treatment for an ongoing infection.
Two designer molecules also attach the virus to a super-tight squeeze, allowing less to do more. “If you have something that binds it well, you don’t need to use that much,” said Attabe Rodriguez Benitez, a biochemist at the University of Michigan who was not involved in the research. “It means that you are getting more bang for your buck.”
Both research groups are exploring their products as potential tools not only to combat infection, but to prevent it, somewhat like a short-term vaccine. In a series of experiments described in their paper, the Neolukin team put their ACE-2 decoy into the hamsters’ nostrils, then exposed the animals to coronaviruses. Untreated hamsters fell dangerously ill, but hamsters receiving nasal spray fared better.
Dr. Carter and his colleagues are currently conducting similar experiments with their mini-binder, and are seeing comparable results.
These findings may not translate into humans, the researchers cautioned. And neither team has yet to work out a proper way to administer their products in animals or people.
Down the line, there may still be opportunities for two types of designer proteins to work together – if not in the same product, at least in a single war, as the epidemic moves on. “It’s very complementary,” Dr. Carter said. If all goes well, such molecules could join public health measures and a growing arsenal of drugs to fight the virus, she said: “This is another tool you might have.”