Genes on the rack

Physicists at LMU have developed a novel nanotool that provides a facile means of characterizing the mechanical properties of biomolecules. Faced with the thousands of proteins and genes found in virtually every cell in the body, biologists want to know how they all work exactly: How do they interact to carry out their specific functions and how do they respond and adapt to perturbations? One of the crucial factors in all of these processes is the question of how biomolecules react to the minuscule forces that operate at the molecular level. LMU physicists led by Professor Tim Liedl , in collaboration with researchers at the Technical University in Braunschweig and at Regensburg University, have come up with a method that allows them to exert a constant force on a single macromolecule with dimensions of a few nanometers, and to observe the molecule's response. The researchers can this way test whether or not a protein or a gene is capable of functioning normally when its structure is deformed by forces of the magnitude expected in the interior of cells. This new method of force spectroscopy uses self-assembled nanoscopic power gauges, requires no macroscopic tools and can analyze large numbers of molecules in parallel, which speeds up the process of data acquisition enormously. With their new approach, the researchers have overcome two fundamental limitations of the most commonly used force spectroscopy instruments. In the case of force microscopy and methodologies based on optical or magnetic tweezers, the molecules under investigation are always directly connected to a macroscopic transducer.