How "out of body experiences" help proteins neutralize chemical agents
Proteins are the workhorses of biology, and while scientists have been able to control them in the body, they're too sensitive to be useful in the outside world. Now, a team from UC Berkeley has found a way to keep them alive and functioning in a synthetic environment, and used them to make mats that can break down toxic chemicals.
In their natural habitat, proteins perform a massive array of critical roles, moving atoms around the body, triggering chemical reactions and fighting off infection. Plenty of research has gone into blocking or improving their functions to help combat cancer, reduce the chance of diabetes or even reverse aging.
But in order to fulfill their specialized functions, proteins are folded into very precise structures, guided by their environment or each other. Outside of the body they tend to fall apart quickly, so using them in synthetic contexts has so far been difficult.
For the new study, the researchers set out to change that. They started by analyzing trends in protein sequences and surfaces, to spot the vital things that would need to be maintained in an artificial environment.
"Proteins have very well-defined statistical pattern, so if you can mimic that pattern, then you can marry the synthetic and natural systems, which allows us to make these materials," says Brian Panganiban, first author of the study.
Using the analysis as a springboard, the Berkeley researchers designed materials that would best mimic the natural necessities for proteins. These materials, called random heteropolymers (RHPs), are made up of chains of four kinds of monomers, in the same way that natural proteins are made of chains of amino acids. This allows the RHPs to act like a synthetic protein, interacting with specific parts of the real ones.
To test them out, the team began with extensive molecular simulations, which showed that the material worked as hoped. The organic proteins folded correctly and survived in the synthetic environment as well as they would in the body.
Next, the researchers put them to work in practical experiments. They made fiber mats by combining the RHP material with another protein called organophosphorus hydrolase (OPH), which degrades the toxic components of chemicals used in insecticides and chemical weapons.
When the mats were immersed in an insecticide, they quickly neutralized the chemical. At its current size, the team found that it only took a matter of minutes for the material to break down about a tenth of its own weight in the toxic chemicals.
The Berkeley researchers say that these RHP mats could be scaled up to help clean up toxic spills or chemical attacks. Their design could also be tweaked to support other proteins, to help tackle a wide variety of other pollution problems.
The research was published in the journal Science.
Source: UC Berkeley