A generation of drugs called monoclonal antibodies, also known as MABs, is altering the landscape of disease treatment by selectively targeting disease-causing agents and kick-starting immune cells. But sending fundamental, engineered proteins into space for further research may reveal ways to make drugs more targeted, concentrated and easier to administer.

MABs make up about one-third of protein-based therapeutics and are most often used to treat cancer and inflammation. They are widely regarded for their ability to target the specific protein of a pathogen and stop it from invading more cells. This means the therapy is tailored to the patient’s disease. The problem, however, is that patients need to get these drugs in large quantities over extended periods of time.

Proteins are too small to study under a microscope, so growing them into crystals lets researchers get a better understanding of their 3D constitution. Their makeup reveals how each protein works and how it contributes to disease growth. Once we understand this, drugs can be developed that mesh with the protein and fight the disease scenarios.

As well as being an important category of therapeutics, proteins are themselves drug targets. Drug design companies need high-resolution protein structures to design suitable drugs.

This is where microgravity comes in.

Earth’s gravity can inhibit the growth and quality of crystals by affecting how the molecules position themselves on the exterior of the crystal. This makes space an ideal environment for this type of research.

AN INVOLVED PROCESS

Dr. David Sheehan, professor of biochemistry in Khalifa University’s department of Chemistry, has been working on a method of crystalizing proteins for 12 years. Now, his proteins are waiting in Japan for a possible February 2024 ride to the International Space Station.

While turning proteins into crystals might seem like a cool magic trick, the process is quite involved. And many of the victories in successful crystallization can be attributed to time, patience and a lot of luck.

CAPTION: David Sheehan, professor of biochemistry-chemistry department, Khalifa University

Sheehan says initially, the protein is purified or separated from anything that might inhibit crystallization, like fatty materials from cells. The pH level is maintained for an optimum growth environment, and salt might be added to increase the ionic strength — or concentration — of the solution.

Other precipitants like polyethylene glycol or organic solvents, which decrease the protein solubility, are added. Then, the conditions are manipulated in a variety of ways, such as adjusting the temperature or exposure to gravity.

The chemical additives and pH combined make up a condition. Most proteins only give crystals in a small number of conditions, so it is necessary to screen thousands of conditions to find the small number that will yield usable crystals.

– Dr. David Sheehan, professor of biochemistry-Chemistry department, Khalifa University

And then it’s a waiting game — crystals might form in a week, a year or not at all.

Sheehan says researchers spend most of their time watching and hoping for a crystal, but most won’t see it: “When and if a crystal appears, then you’ve got a project.”

In his case, the crystals responded well to the addition of nanoparticles. While most of these types of experiments might typically result in one or two crystals from thousands, Sheehan’s team grew 15 crystals out of a panel of 16 proteins studied.

“We found one formulation that worked better than the others. So, then we used that nanoparticle with about 200 conditions,” he tells KUST Review.

This is unheard of, he says. And he knew they were on to something significant.

CAPTION: Crystals of protein Furin grown on Earth IMAGE: Khalifa University

When the UAE space program was asked to send protein samples to Japan for testing and a possible spot on the 2024 mission to the International Space Station, Sheehan believed his team had a good shot at it. The crystals are in Japan for final testing.

JOURNEY TO SPACE

The project has a long history.

Sheehan grew his first nanoparticle-doped protein crystal over a decade ago, the result of an idea that had been brewing, a fridge full of available proteins, a student looking for a project and a friend with access to a synchrotron, a machine that uses electricity to create intense X-ray beams to study matter’s chemical and structural properties.

The student experimented with two nanoparticles, different from the ones they used on the recent project: “The crystals grew very quickly and in the presence of a nanoparticle, they were larger, they grew faster, and they really grew. And that worked with both nanoparticles,” he says.

The stars (or crystals rather) aligned, and Sheehan and his student were soon transporting proteins to Dublin to a crystallographer friend who agreed to take them to the Paris synchrotron.

A synchrotron is about the size of a football stadium and is an ideal way to determine the three-dimensional atomic structure of a protein. It involves the crystallization of the protein and an in-depth analysis using a method called X-ray diffraction, Sheehan says.

Here, an X-ray beam is sent through the crystal. This interacts with the atoms in the crystal’s network, which scatter, creating a pattern. The pattern is recorded, and multiple images are created by rotating the protein, collecting further patterns and creating a map. The data is analyzed and a 3D structure is created.

FOCUS ON PROTEINS

But why are we so focused on proteins? Why not other molecules?

Proteins are the worker bees of a cell. They play an essential role in most biological systems and are responsible for most cellular functions. They are responsible for the shape, the interior design, production, cleanup, general upkeep and communication of cells. This makes them of great interest for targeted drug development, Sheehan says.

There are more than 130 protein-based therapeutics on the market, and the next step is to make them even better.

Current drugs for diseases like cancer, for example, require patients to take them for lengthy periods. Patients might sit in a clinic, hooked up to an IV for hours at a time, to ensure they get the right concentration of treatment. These treatments can go on for months or years. Imagine if they could receive a simple injection in a doctor’s office. This is something pharmaceutical giant Merck is working on.

And this type of drug development is dependent on research like that of Sheehan and his team.

CAPTION: Structure of Furin obtained by Cryo-EM of crystals IMAGE: Khalifa University

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For example furin, the protein in Japan at present, is a potential antiviral drug target for treating COVID-19.

Aside from the contributions to science, fighting disease and improving patient care, it could also mean a commercial venture.

“This could be very big,” Sheehan says. “I can see two options for commercialization, one of which is to market this as a crystallization screen and the other a start-up offering this as a service.”

With the team’s current success rate of more than 90 percent, it’s promising.

Sheehan and his researcher Salma Sultana Syed have now patented their screen in the USA and UAE with a patent in Europe pending. They are exploring creating a start-up to be called ProScreenix.

According to Allied Market Research, the protein therapeutics global market value is expected to reach U.S.$566.6 billion by 2030, up from U.S.$283.64 billion in 2020.