Findings could lead to eco-friendly plastics and other materials
UC Berkeley professor Ting Xu has spent more than seven years trying to figure out how to design synthetic polymers with protein-like behaviors. Now, she and a team of researchers have unlocked “design rules” that upend long-held views on polymers and could pave the way for eco-friendly plastics and other materials.
As reported today in Nature, the researchers, including MIT professor Alfredo Alexander-Katz, discovered something “wild” when they set out to design polymers as synthetic enzymes: Though their synthetic enzyme couldn’t fold like a natural protein, and its underlying molecular structure was slightly different, it could still mimic the behavior of a natural enzyme.
According to Xu, professor of materials science and engineering and of chemistry, the key lies in the polymer’s ability to bend, twist and easily change the shape of its carbon “backbone.” This flexibility not only compensated for any structural differences between the lab-created and natural versions, but it also enabled the synthetic enzyme to surpass the functional capabilities of a natural enzyme.
“This work is philosophically a quantum leap for us,” said Xu, who is also a faculty scientist at Lawrence Berkeley National Laboratory. “I went from thinking that I won’t be able to replicate the function of the proteins until I can replicate their exact structure and monomeric sequencing, to now seeing a viable pathway. It fundamentally shifts my view on how we should design bioinspired materials.”
A highly collaborative effort, this investigation brought together researchers from UC Berkeley; MIT; University of Illinois Urbana-Champaign; University of California, Davis; and University of Michigan.
According to Xu, identifying these design rules could lay the groundwork for future research and applications. “This foundational knowledge will enable us to produce functional polymers that meet technological needs in a range of areas, from the life sciences and energy to the environment,” she said.
One long-range goal is to use this knowledge to “re-imagine the plastics industry” and solve the ongoing compatibility issues between our need for plastics and their environmental impact. “If we design the polymer right, we may be able to develop plastics that meet both our current durability requirements and future environmental goals,” she said.
Xu added that understanding this translation mechanism will also enable the design of new materials that can do things that natural enzymes can’t — like safely break down antibiotics that pollute our waterways.
“This work is the culmination of many years of research,” she said. “It shows the importance of basic science and how it can open the door to exciting possibilities.”
This research was supported by the U.S. Defense Threat Reduction Agency, the U.S. Department of Defense, the National Science Foundation and the Laboratory Directed Research and Development (LDRD) Program at Lawrence Berkeley National Laboratory.
Read this story on Berkeley Engineering.