lipid가 아닌, RNA와 protein으로 vesicle만들기.

These bubble-like entities—which form spontaneously when specific protein and RNA molecules are mixed in an aqueous buffer solution—hold potential as biological storage compartments. They could serve as an alternative to traditional vesicles that are made from water-insoluble organic compounds called lipids, researchers say.

"Our discovery has widespread implications, from understanding basic cell biology to enabling possible biotechnological applications, such as targeted drug delivery or pesticide release," says Priya Banerjee, Ph.D., assistant professor of physics in the University at Buffalo College of Arts and Sciences. "These hollow spheres look and behave like the classical lipid vesicles that people have been utilizing in bioengineering applications for many years, with an important exception: They are not made by lipids."

"Because of the hollow structure resembling lipid vesicles, one may envision a potentially exciting application where protein-RNA vesicles are dispatched into cells for carrying out rescue missions by releasing biomolecules or changing the local subcellular environment," says Davit Potoyan, Ph.D., assistant professor of chemistry at Iowa State University. "Another reason to be excited is that these vesicles are formed spontaneously from naturally occurring proteins and nucleic acids, which may help to avoid issues of toxicity that might be seen in other polymers designed to mimic lipid vesicles."

To make the micron-sized vesicles, scientists mixed naturally occurring cationic proteins with RNA in an aqueous buffer solution. At some concentrations, the protein and RNA molecules clustered together to produce liquid droplets, akin to beads of oil floating in water. But at other concentrations, the protein and RNA instead came together to form the bubble-like vesicles.

As part of the research, the team also mapped out the conditions under which each type of structure forms. Experiments and simulations showed that the protein-RNA complexes coalesce spontaneously and are held together because of weak electrostatic attraction, repulsive interactions and chain entropy. A delicate balance of these forces dictates whether liquid droplets or hollow vesicles will form, the researchers say.

reference

Ibraheem Alshareedah et al, Phase transition of RNA−protein complexes into ordered hollow condensates, Proceedings of the National Academy of Sciences (2020). DOI: 10.1073/pnas.1922365117