DNA nanostructure flips lipids from one side of a lipid bilayer to the other more than 1,000 times as fast as natural enzymes called scramblases, researchers report (Nat. Commun. 2018, DOI: 10.1038/s41467-018-04821-5).
Asymmetry in the lipid composition of the inner and outer leaflets of biological membranes is essential to proper functioning of cells. To maintain this asymmetry, three classes of enzymes control movement of lipids between the inner and outer leaflets of membranes. One class, the scramblases, randomly moves lipids between layers to equilibrate the membrane composition, which can trigger cell death via apoptosis. Malfunctioning scramblases are associated with diseases such as Scott syndrome, in which blood doesn’t coagulate properly.
The DNA nanostructures reported by Ulrich F. Keyser of the University of Cambridge; Aleksei Aksimentiev of the University of Illinois, Urbana-Champaign; and coworkers act like synthetic scramblases. But that’s not what the researchers were originally looking for.
“We were interested in engineering DNA channels to act as artificial ion channels,” Aksimentiev says. They ran computer simulations of DNA nanostructures that Keyser’s group had previously made as ion channels. The nanostructures have eight DNA strands, two of which have cholesterol at one end to anchor the structure in the membrane.
– Written by the CCIL Communications Team (for ES or Name, Title to recognize author)