Ludwig-Maximillians -- The search for new therapeutic agents is time-consuming and expensive. Pharmaceutical companies may have to screen thousands of compounds for the ability to bind a target molecule before they hit upon a promising drug candidate. A group of Biophysicists at LMU Munich led by Professor Dieter Braun, a member of the Cluster of Excellence “Nanosystems Initiative Munich” (NIM), and a partner in NanoTemper (an LMU spin-off), have now developed a unique technology called “microscale thermophoresis” that allows to measure intereactions under close-to-native conditions, thus improving the decision making process in drug development. The technique takes advantage of the Soret effect – the tendency of molecules to drift along temperature gradients, usually from warm to cold. If a compound encounters and binds to another molecule, its thermophoretic parameters change, and its trajectory may even be reversed. This phenomenon can be exploited to determine whether a molecule that is known to play a causative role in a given disease binds to a test substance. In the test, which can be carried out directly on blood samples, the thermodiffusion of a labelled biomolecule of interest is measured in the presence and absence of a candidate binding agent. If the two bind together to form a complex, the resulting change in their thermophoretic behaviour can be detected. “Detection of binding activity is the first step on the road to a new drug”, says Braun. “The new method also has potential applications in medical diagnostics, and in food and environmental monitoring.”
