By Will Soutter
LMU scientists have successfully created a functional complex with nanometer accuracy by placing two biomolecules close to each other with the help of an atomic force microscope.
The study results have been reported in the Nanoletters journal. Professor Hermann Gaub, a LMU physicist, and colleagues have developed a technique, in which the atomic force microscope’s needle-sharp tip is used for extracting individual molecules from a substrate and placing them in designated positions with an accuracy of a few nanometers. The researchers have used this ‘single-molecule cut-and-paste’ technique to pick and place inactive single-molecule building blocks for building an active molecular complex.
The researchers used two short RNA strands for building the complex. They picked one RNA strand from a depository using the atomic force microscope and placed it nearby the second RNA strand positioned somewhere else on the substrate. When the strands contacted each other, they spontaneously created an aptamer, which is a three-dimensional pocket that can bind with a target molecule. Here, fluorescent dye malachite green was the target molecule. The binding interplay increases the fluorescence released by the target by over 1000 times, which means that the aptamer’s two parts have been assembled accurately.
Mathias Strackharn, lead author of the study, informed that the researchers are able to accurately control the assembly process. This single-molecule cut-and-paste process enables the researchers to build systems whose inherent function relies on the arrangement of their molecular components. This capability will in turn allow them to analyze the role of interplays between the components in deciding the functions of molecular complexes.