Synthetic protein binds to VX nerve agent

VX is an odorless, tasteless, human-made chemical compound that works by attacking the nervous system, causing muscle paralysis and death via asphyxiation within minutes. Above, an M23 VX landmine. (Credit: Wikimedia Commons)

A new synthetic protein quickly detects molecules of a deadly nerve agent, VX.

The development could pave the way for a new generation of tailor-made biosensors and treatments that could be deployed against the chemical warfare agent.

As described in Science Advances, the team created the protein through a special design on high-speed computers.

“We’ve made an artificial protein that binds a chemical target—in this case, the VX nerve agent,” says Vikas Nanda, a scientist at the Center for Advanced Biotechnology and Medicine (CABM) at Rutgers University, and an author of the study in Science Advances.

“We wanted to design it to generate a signal that could be coupled to a device, making a biosensor for chemical weapons. And we’ve been able to achieve that.”

VX is an odorless, tasteless, human-made chemical compound that is the most toxic and rapidly acting of any of the known chemical warfare agents. It works by attacking the nervous system, causing muscle paralysis and death via asphyxiation within minutes.

Because the United Nations has classified VX as a weapon of mass destruction, countries are banned from stockpiling it. However, nations are permitted to store small amounts for research.

The researchers designed the protein to have a cavity at its center that matched the precise shape and chemical composition of VX. Collaborators at the City College of New York took the Rutgers design and produced a real version of the protein, purified it, and shipped the sample on ice overnight to an approved chemical weapon testing facility, MRIGlobal in Kansas City, Missouri. There, researchers tested the protein against VX within 24 hours.

“The protein underwent a dramatic shape change, burying VX in the cavity we designed,” says Nanda, also a professor in the department of biochemistry and molecular biology at Rutgers Robert Wood Johnson Medical School. “This shape change is the signal which could be coupled to a sensor device.”

The protein can detect VX at levels a thousand times more sensitive than current technologies, Nanda says. In addition, the protein doesn’t produce false positives that occur when present-day sensors accidentally detect non-nerve agent chemicals which are similar, like some pesticides.

According to the US Centers for Disease Control and Prevention website, VX or other nerve agents were possibly used in chemical warfare during the Iran-Iraq War in the 1980s. Chemical weapons experts have alleged it also has been used more recently in warfare and, in one case, an assassination. While antidotes are available for VX, they are most useful if given as soon as possible after exposure.

“The design method presented here should enable the development of a new generation of biosensors, therapeutics, and diagnostics,” Nanda says.

Douglas Pike, a graduate student at CABM, contributed to the study. Additional coauthors are from City College of New York and Clarkson University.

Source: Rutgers University