Netting proteins, one at a time
Ever tried catching fish by hand? Fast and slippery, the fish easily escapes —unless, of course, the hand is holding a fishing net. Catching single proteins has been an outstanding technological challenge because of their small size (about 10 nm) and the stochastic Brownian forces that dominate protein motion at the nanoscale. Methods have been devised to adsorb proteins onto surfaces or to target specific proteins for analysis using antibodies, but such approaches typically produce permanent attachment of the proteins to their macroscopic handles. Writing in Nature Nanotechnology, Schmid and co-workers report a catch-and-release nanopore trap capable of holding single proteins for hours, giving ample time for single-molecule characterization of the protein shape.