Scientists find enzymes in nature that could replace toxic chemicals
Some 900 miles off the coast of Portugal, nine major islands rise from the mid-Atlantic. Verdant and volcanic, the Azores archipelago hosts a wealth of biodiversity that keeps field research scientist, Marlon Clark, returning for more. “You’ve got this really interesting biogeography out there,” says Clark. “There’s real separation between the continents, but there’s this inter-island dispersal of plants and seeds and animals.”
It’s a visual paradise by any standard, but on a microscopic level, there’s even more to see. The Azores’ nutrient-rich volcanic rock — and its network of lagoons, cave systems, and thermal springs — is home to a vast array of microorganisms found in a variety of microclimates with different elevations and temperatures.
Clark works for Basecamp Research, a biotech company headquartered in London, and his job is to collect samples from ecosystems around the world. By extracting DNA from soil, water, plants, microbes and other organisms, Basecamp is building an extensive database of the Earth’s proteins. While DNA itself isn’t a protein, the information stored in DNA is used to create proteins, so extracting, sequencing, and annotating DNA allows for the discovery of unique protein sequences.
Using what they’re finding in the middle of the Atlantic and beyond, Basecamp’s detailed database is constantly growing. The outputs could be essential for cleaning up the damage done by toxic chemicals and finding alternatives to these chemicals.
Catalysts for change
Proteins provide structure and function in all living organisms. Some of these functional proteins are enzymes, which quite literally make things happen.
“Industrial chemistry is heavily polluting, especially the chemistry done in pharmaceutical drug development. Biocatalysis is providing advantages, both to make more complex drugs and to be more sustainable, reducing the pollution and toxicity of conventional chemistry," says Ahir Pushpanath, who heads partnerships for Basecamp.
“Enzymes are perfectly evolved catalysts,” says Ahir Pushpanath, a partnerships lead at Basecamp. ”Enzymes are essentially just a polymer, and polymers are made up of amino acids, which are nature’s building blocks.” He suggests thinking about it like Legos — if you have a bunch of Lego pieces and use them to build a structure that performs a function, “that’s basically how an enzyme works. In nature, these monuments have evolved to do life’s chemistry. If we didn’t have enzymes, we wouldn’t be alive.”
In our own bodies, enzymes catalyze everything from vision to digesting food to regrowing muscles, and these same types of enzymes are necessary in the pharmaceutical, agrochemical and fine chemical industries. But industrial conditions differ from those inside our bodies. So, when scientists need certain chemical reactions to create a particular product or substance, they make their own catalysts in their labs — generally through the use of petroleum and heavy metals.
These petrochemicals are effective and cost-efficient, but they’re wasteful and often hazardous. With growing concerns around sustainability and long-term public health, it's essential to find alternative solutions to toxic chemicals. “Industrial chemistry is heavily polluting, especially the chemistry done in pharmaceutical drug development,” Pushpanath says.
Basecamp is trying to replace lab-created catalysts with enzymes found in the wild. This concept is called biocatalysis, and in theory, all scientists have to do is find the right enzymes for their specific need. Yet, historically, researchers have struggled to find enzymes to replace petrochemicals. When they can’t identify a suitable match, they turn to what Pushpanath describes as “long, iterative, resource-intensive, directed evolution” in the laboratory to coax a protein into industrial adaptation. But the latest scientific advances have enabled these discoveries in nature instead.
Marlon Clark, a research scientist at Basecamp Research, looks for novel biochemistries in the Azores.
Glen Gowers
Enzyme hunters
Whether it’s Clark and a colleague setting off on an expedition, or a local, on-the-ground partner gathering and processing samples, there’s a lot to be learned from each collection. “Microbial genomes contain complete sets of information that define an organism — much like how letters are a code allowing us to form words, sentences, pages, and books that contain complex but digestible knowledge,” Clark says. He thinks of the environmental samples as biological libraries, filled with thousands of species, strains, and sequence variants. “It’s our job to glean genetic information from these samples.”
“We can actually dream up new proteins using generative AI," Pushpanath says.
Basecamp researchers manage this feat by sequencing the DNA and then assembling the information into a comprehensible structure. “We’re building the ‘stories’ of the biota,” Clark says. The more varied the samples, the more valuable insights his team gains into the characteristics of different organisms and their interactions with the environment. Sequencing allows scientists to examine the order of nucleotides — the organic molecules that form DNA — to identify genetic makeups and find changes within genomes. The process used to be too expensive, but the cost of sequencing has dropped from $10,000 a decade ago to as low as $100. Notably, biocatalysis isn’t a new concept — there have been waves of interest in using natural enzymes in catalysis for over a century, Pushpanath says. “But the technology just wasn’t there to make it cost effective,” he explains. “Sequencing has been the biggest boon.”
AI is probably the second biggest boon.
“We can actually dream up new proteins using generative AI,” Pushpanath says, which means that biocataylsis now has real potential to scale.
Glen Gowers, the co-founder of Basecamp, compares the company’s AI approach to that of social networks and streaming services. Consider how these platforms suggest connecting with the friends of your friends, or how watching one comedy film from the 1990s leads to a suggestion of three more.
“They’re thinking about data as networks of relationships as opposed to lists of items,” says Gowers. “By doing the same, we’re able to link the metadata of the proteins — by their relationships to each other, the environments in which they’re found, the way those proteins might look similar in sequence and structure, their surrounding genome context — really, this just comes down to creating a searchable network of proteins.”
On an Azores island, this volcanic opening may harbor organisms that can help scientists identify enzymes for biocatalysis to replace toxic chemicals.
Emma Bolton
Uwe Bornscheuer, professor at the Institute of Biochemistry at the University of Greifswald, and co-founder of Enzymicals, another biocatalysis company, says that the development of machine learning is a critical component of this work. “It’s a very hot topic, because the challenge in protein engineering is to predict which mutation at which position in the protein will make an enzyme suitable for certain applications,” Bornscheuer explains. These predictions are difficult for humans to make at all, let alone quickly. “It is clear that machine learning is a key technology.”
Benefiting from nature’s bounty
Biodiversity commonly refers to plants and animals, but the term extends to all life, including microbial life, and some regions of the world are more biodiverse than others. Building relationships with global partners is another key element to Basecamp’s success. Doing so in accordance with the access and benefit sharing principles set forth by the Nagoya Protocol — an international agreement that seeks to ensure the benefits of using genetic resources are distributed in a fair and equitable way — is part of the company's ethos. “There's a lot of potential for us, and there’s a lot of potential for our partners to have exactly the same impact in building and discovering commercially relevant proteins and biochemistries from nature,” Clark says.
Bornscheuer points out that Basecamp is not the first company of its kind. A former San Diego company called Diversa went public in 2000 with similar work. “At that time, the Nagoya Protocol was not around, but Diversa also wanted to ensure that if a certain enzyme or microorganism from Costa Rica, for example, were used in an industrial process, then people in Costa Rica would somehow profit from this.”
An eventual merger turned Diversa into Verenium Corporation, which is now a part of the chemical producer BASF, but it laid important groundwork for modern companies like Basecamp to continue to scale with today’s technologies.
“To collect natural diversity is the key to identifying new catalysts for use in new applications,” Bornscheuer says. “Natural diversity is immense, and over the past 20 years we have gained the advantages that sequencing is no longer a cost or time factor.”
This has allowed Basecamp to rapidly grow its database, outperforming Universal Protein Resource or UniProt, which is the public repository of protein sequences most commonly used by researchers. Basecamp’s database is three times larger, totaling about 900 million sequences. (UniProt isn’t compliant with the Nagoya Protocol, because, as a public database, it doesn’t provide traceability of protein sequences. Some scientists, however, argue that Nagoya compliance hinders progress.)
“Eventually, this work will reduce chemical processes. We’ll have cleaner processes, more sustainable processes," says Uwe Bornscheuer, a professor at the University of Greifswald.
With so much information available, Basecamp’s AI has been trained on “the true dictionary of protein sequence life,” Pushpanath says, which makes it possible to design sequences for particular applications. “Through deep learning approaches, we’re able to find protein sequences directly from our database, without the need for further laboratory-directed evolution.”
Recently, a major chemical company was searching for a specific transaminase — an enzyme that catalyzes a transfer of amino groups. “They had already spent a year-and-a-half and nearly two million dollars to evolve a public-database enzyme, and still had not reached their goal,” Pushpanath says. “We used our AI approaches on our novel database to yield 10 candidates within a week, which, when validated by the client, achieved the desired target even better than their best-evolved candidate.”
Basecamp’s other huge potential is in bioremediation, where natural enzymes can help to undo the damage caused by toxic chemicals. “Biocatalysis impacts both sides,” says Gowers. “It reduces the usage of chemicals to make products, and at the same time, where contamination sites do exist from chemical spills, enzymes are also there to kind of mop those up.”
So far, Basecamp's round-the-world sampling has covered 50 percent of the 14 major biomes, or regions of the planet that can be distinguished by their flora, fauna, and climate, as defined by the World Wildlife Fund. The other half remains to be catalogued — a key milestone for understanding our planet’s protein diversity, Pushpanath notes.
There’s still a long road ahead to fully replace petrochemicals with natural enzymes, but biocatalysis is on an upward trajectory. "Eventually, this work will reduce chemical processes,” Bornscheuer says. “We’ll have cleaner processes, more sustainable processes.”
This spring, just like any other year, thousands of young North American engineers will graduate from their respective colleges ready to start erecting buildings, assembling machinery, and programming software, among other things. But before they take on these complex and important tasks, many of them will recite a special vow stating their ethical obligations to society, not unlike the physicians who take their Hippocratic Oath, affirming their ethos toward the patients they would treat. At the end of the ceremony, the engineers receive an iron ring, as a reminder of their promise to the millions of people their work will serve.
The ceremony isn’t just another graduation formality. As a profession, engineering has ethical weight. Moreover, engineering mistakes can be even more deadly than medical ones. A doctor’s error may cost a patient their life. But an engineering blunder may bring down a plane or crumble a building, resulting in many more fatalities. When larger projects—such as fracking, deep-sea mining or building nuclear reactors—malfunction and backfire, they can cause global disasters, afflicting millions. A vow that reminds an engineer that their work directly affects humankind and their planet is no less important than a medical oath that summons one to do no harm.
The tradition of taking an engineering oath began over a century ago in Canada. In 1922, Herbert E.T. Haultain, professor of mining engineering at the University of Toronto, presented the idea at the annual meeting of the Engineering Institute of Canada. The seven past presidents of that body were in attendance, heard Haultain’s speech and accepted his suggestion to form a committee to create an honor oath. Later, they formed the nonprofit Corporation of the Seven Wardens, which would oversee the ritual. Next year, in 1923, with the encouragement of the Seven Wardens, Haultain wrote to poet and writer Rudyard Kipling, asking him to develop a professional oath for engineers. “We are a tribe—a very important tribe within the community,” Haultain said in the letter, “but we are lacking in tribal spirit, or perhaps I should say, in manifestation of tribal spirit. Also, we are inarticulate. Can you help us?”
While Kipling is most famous now for “The Jungle Book” and perhaps his poem “Gunga Din,” he had also written a short story about engineers, “The Bridge Builders.” His poem “The Sons of Martha” can be read as a celebration of engineers:
It is their care in all the ages to take the buffet and cushion the shock.
It is their care that the gear engages; it is their care that the switches lock.
It is their care that the wheels run truly; it is their care to embark and entrain,
Tally, transport, and deliver duly the Sons of Mary by land and main.
Kipling accepted the ask and wrote the Ritual of the Calling of an Engineer, which he sent to Haultain a month later. In his response to Haultain, he stated that he preferred the word “Obligation” to “Oath.” He wrote the Obligation using Old English lettering and the old-fashioned capitalization. Kipling’s Obligation binds engineers upon their “Honor and Cold Iron” to not “suffer or pass, or be privy to the passing of, Bad Workmanship or Faulty Material,” and pardon is asked “in the presence of my betters and my equals in my Calling” for the engineer’s “assured failures and derelictions.” The hope is that when one is tempted to shoddy work by weakness or weariness, the memory of the Obligation “and the company before whom it was entered into, may return to me to aid, comfort, and restrain.”
Using the Obligation, The Seven Wardens created an induction ceremony, which seeks to unify the profession and recognize engineering’s ethics, including responsibility to the public and the need to make the best decisions possible. The induction ceremony included recitation of Kipling’s “Obligation” and incorporated an anvil, a hammer, an iron chain, and an iron ring. The inductee engineers sat inside an area marked off by the iron chain, with their more senior colleagues outside that area. At the start of the ritual, the leader beat out S-S-T in Morse code with the hammer and anvil—the letters standing for Steel, Stone, and Time. A more experienced and previously obligated engineer placed the ring on the small finger of the inductee engineer’s working hand. As per Kipling, the ring’s rough, faceted texture symbolized “the young engineer’s mind” and the difficulties engineers face in mastering their discipline.
A persistent myth purports that the original iron rings were made from the beams or bolts of the Quebec Bridge that failed twice during construction.
The first induction ceremony took place on April 25, 1925, in Montreal to obligate two of the Seven Wardens, along with four graduates from the University of Toronto class of 1893. On May 1 of that year, 14 more engineers were obligated at the University of Toronto. From that time to today most Canadian professional engineers have gone through that same ritual in their various camps, called Kipling camps—local chapters associated with various Canadian universities.
Henry Petroski, Duke University’s professor of civil engineering and history, notes in his book, “Forgive Design: Understanding Failure,” that Kipling’s poem “Sons of Martha” is often read as part of the ritual. However, sometimes inductees read Kipling’s “Hymn of Breaking Strain,” instead, which graphically depicts disastrous outcomes of engineering mistakes. The first stanza of that poem says:
The careful text-books measure
(Let all who build beware!)
The load, the shock, the pressure
Material can bear.
So, when the buckled girder
Lets down the grinding span,
'The blame of loss, or murder,
Is laid upon the man.
Not on the Stuff—the Man!
As if to strengthen the importance of these concepts, a persistent myth purports that the original iron rings were made from the beams or bolts of the Quebec Bridge that failed twice during construction. The bridge spans the St. Lawrence River upriver from Quebec City, and at the time of its construction was the world’s longest at 1,800 feet. Due to engineering errors and poor oversight, the bridge’s own weight exceeded its carrying capacity. Moreover, engineers downplayed danger when bridge beams began to warp under stress, saying that they were probably warped before they were installed. On August 29, 1907, the bridge collapsed, killing 75 of 86 workers. A second collapse occurred in 1916 when lifting equipment failed, and thirteen more workers died.
The ring myth, however, couldn’t be true. The original iron rings couldn’t have come from the failed bridge since it was made of steel, not wrought iron. Today the rings are made from stainless steel because iron deteriorates and stains engineers’ finger black.
On August 14, 2018, Morandi Bridge over Polcevera River in Genoa, Italy, collapsed from structural failure, killing 43 people.
Adobe Stock
The Seven Wardens decided to restrict the ritual to engineers trained in Canada. They copyrighted the obligation oath in Canada and the United States in 1935. Although the ritual is not a requirement for professional licensing, just like the Hippocratic Oath is not part of medical licensing, it remains a long-standing tradition.
The American Obligation of the Engineer has its own creation story, albeit a very different one. The American Order of the Engineer (OOE) was initiated in 1970, during the era of the anti-war protests, Apollo missions and the first Earth Day. On May 4, 1970, the National Guard shot into a crowd of protesters at Kent State University, killing four people. The two authors of the American obligation—Cleveland State University’s (CSU) engineering professor John Janssen and his wife Susan—reflected these historical events in the oath they wrote. Their version of the oath binds engineers to “practice integrity and fair dealing.” It also notes that their “skill carries with it the obligation to serve humanity by making the best use of the Earth’s precious wealth.” As Petroski explains in his book, “campus antiwar protestors around the country tended to view engineers as complicit in weapons proliferation [which] prompted some [CSU] engineering student leaders to look for a means of asserting some more positive values.”
Kip A. Wedel, associate professor of history and politics at Bethel College, wrote in his book, “The Obligation: A History of the Order of the Engineer,” that the ceremony was not a direct response to the Kent State shootings—it was already scheduled when the shootings happened. Yet, engineering students found the ceremony a positive action they could take in contrast to the overall turmoil. The first American ritual took place on June 4, 1970, at CSU. In total, 170 students, faculty members, and practicing engineers took the obligation. This established CSU as the first Link of the Order, as the OOE designates its local chapters. For their first ceremony, the CSU students fabricated smooth, unfaceted rings from stainless steel pipe. Later they were replaced by factory-made rings. According to Paula Ostaff, OOE’s Executive Director, about 20,000 eligible students and alumni obligate themselves yearly.
Societies hope that every engineer is imbued with a strong ethical sense and that their pledges are never far from mind. For some, the rings they wear serve a daily reminder that every paper they sign off on is touched by a physical reminder of their commitment.
These ethical and responsible engineering practices are especially salient today, when one in three American bridges needs repair or replacement, some have already collapsed, and engineers are working on projects related to the bipartisan infrastructure bill President Biden signed into law in 2021. Canada has committed $33 billion to its Investing in Canada Infrastructure Program. At the heart of these grand projects are many thousands of professional engineers, collectively working millions of hours. The professional vows they took aim to assure that the homes, bridges and airplanes they build will work as expected.
In the 1966 movie "Fantastic Voyage," actress Raquel Welch and her submarine were shrunk to the size of a cell in order to eliminate a blood clot in a scientist's brain. Now, 55 years later, the scenario is becoming closer to reality.
California-based startup Bionaut Labs has developed a nanobot about the size of a grain of rice that's designed to transport medication to the exact location in the body where it's needed. If you think about it, the conventional way to deliver medicine makes little sense: A painkiller affects the entire body instead of just the arm that's hurting, and chemotherapy is flushed through all the veins instead of precisely targeting the tumor.
"Chemotherapy is delivered systemically," Bionaut-founder and CEO Michael Shpigelmacher says. "Often only a small percentage arrives at the location where it is actually needed."
But what if it was possible to send a tiny robot through the body to attack a tumor or deliver a drug at exactly the right location?
Several startups and academic institutes worldwide are working to develop such a solution but Bionaut Labs seems the furthest along in advancing its invention. "You can think of the Bionaut as a tiny screw that moves through the veins as if steered by an invisible screwdriver until it arrives at the tumor," Shpigelmacher explains. Via Zoom, he shares the screen of an X-ray machine in his Culver City lab to demonstrate how the half-transparent, yellowish device winds its way along the spine in the body. The nanobot contains a tiny but powerful magnet. The "invisible screwdriver" is an external magnetic field that rotates that magnet inside the device and gets it to move and change directions.
The current model has a diameter of less than a millimeter. Shpigelmacher's engineers could build the miniature vehicle even smaller but the current size has the advantage of being big enough to see with bare eyes. It can also deliver more medicine than a tinier version. In the Zoom demonstration, the micorobot is injected into the spine, not unlike an epidural, and pulled along the spine through an outside magnet until the Bionaut reaches the brainstem. Depending which organ it needs to reach, it could be inserted elsewhere, for instance through a catheter.
"The hope is that we can develop a vehicle to transport medication deep into the body," says Max Planck scientist Tian Qiu.
Imagine moving a screw through a steak with a magnet — that's essentially how the device works. But of course, the Bionaut is considerably different from an ordinary screw: "At the right location, we give a magnetic signal, and it unloads its medicine package," Shpigelmacher says.
To start, Bionaut Labs wants to use its device to treat Parkinson's disease and brain stem gliomas, a type of cancer that largely affects children and teenagers. About 300 to 400 young people a year are diagnosed with this type of tumor. Radiation and brain surgery risk damaging sensitive brain tissue, and chemotherapy often doesn't work. Most children with these tumors live less than 18 months. A nanobot delivering targeted chemotherapy could be a gamechanger. "These patients really don't have any other hope," Shpigelmacher says.
Of course, the main challenge of the developing such a device is guaranteeing that it's safe. Because tissue is so sensitive, any mistake could risk disastrous results. In recent years, Bionaut has tested its technology in dozens of healthy sheep and pigs with no major adverse effects. Sheep make a good stand-in for humans because their brains and spines are similar to ours.
The Bionaut device is about the size of a grain of rice.
Bionaut Labs
"As the Bionaut moves through brain tissue, it creates a transient track that heals within a few weeks," Shpigelmacher says. The company is hoping to be the first to test a nanobot in humans. In December 2022, it announced that a recent round of funding drew $43.2 million, for a total of 63.2 million, enabling more research and, if all goes smoothly, human clinical trials by early next year.
Once the technique has been perfected, further applications could include addressing other kinds of brain disorders that are considered incurable now, such as Alzheimer's or Huntington's disease. "Microrobots could serve as a bridgehead, opening the gateway to the brain and facilitating precise access of deep brain structure – either to deliver medication, take cell samples or stimulate specific brain regions," Shpigelmacher says.
Robot-assisted hybrid surgery with artificial intelligence is already used in state-of-the-art surgery centers, and many medical experts believe that nanorobotics will be the instrument of the future. In 2016, three scientists were awarded the Nobel Prize in Chemistry for their development of "the world's smallest machines," nano "elevators" and minuscule motors. Since then, the scientific experiments have progressed to the point where applicable devices are moving closer to actually being implemented.
Bionaut's technology was initially developed by a research team lead by Peer Fischer, head of the independent Micro Nano and Molecular Systems Lab at the Max Planck Institute for Intelligent Systems in Stuttgart, Germany. Fischer is considered a pioneer in the research of nano systems, which he began at Harvard University more than a decade ago. He and his team are advising Bionaut Labs and have licensed their technology to the company.
"The hope is that we can develop a vehicle to transport medication deep into the body," says Max Planck scientist Tian Qiu, who leads the cooperation with Bionaut Labs. He agrees with Shpigelmacher that the Bionaut's size is perfect for transporting medication loads and is researching potential applications for even smaller nanorobots, especially in the eye, where the tissue is extremely sensitive. "Nanorobots can sneak through very fine tissue without causing damage."
In "Fantastic Voyage," Raquel Welch's adventures inside the body of a dissident scientist let her swim through his veins into his brain, but her shrunken miniature submarine is attacked by antibodies; she has to flee through the nerves into the scientist's eye where she escapes into freedom on a tear drop. In reality, the exit in the lab is much more mundane. The Bionaut simply leaves the body through the same port where it entered. But apart from the dramatization, the "Fantastic Voyage" was almost prophetic, or, as Shpigelmacher says, "Science fiction becomes science reality."
This article was first published by Leaps.org on April 12, 2021.