https://phys.org/news/2019-01-scientists-coax-proteins-synthetic-method.html

As a proof of concept, the team built tiny structures that resemble two doughnuts stacked on top of each other by applying electrical charges to specific spots on naturally occurring proteins. Previous researchers have managed to create synthetic structures from proteins but only after painstakingly affixing something onto proteins or creating new proteins from scratch, making earlier methods complicated, time-intensive and limiting. By contrast, the new method, dubbed "SUpercharged PRotein Assembly (SuPrA)," mimics the way that proteins in living organisms work as they make the molecular machines that carry out the different functions of life: The structures in the new method are self-assembling and flexible.

"Our approach takes a protein that doesn't normally assemble, and gives it many potential sites where it might be able to, allowing it to 'choose' which fits the rest of its geometry and chemistry best," said Anna Simon, a postdoctoral researcher in UT Austin's Department of Molecular Biosciences and co-first author of the paper. "This is important because it gives us a way to semi-direct proteins to organize into larger structures without having to understand beforehand exactly how they will fit together."