Tracking down the molecular mechanisms of the sense of touch 

Researchers at the “Nano-Optics” division at MPL, led by director Prof. Vahid Sandoghdar, are gaining insights into the complex and variable molecular structure of the PIEZO protein by observing it under a cryo-light microscope. The team is developing novel optical methods to study molecules and particles on the nanometer scale. A nanometer is one millionth of a millimeter in length. Measurement is conducted based on the ultra-precise detection of individual molecules. For this, scientists mark each protein with three fluorescent molecules which function like little flashlights to reveal their position and the three-dimensional structure of the protein. These molecules usually fade very quickly at room tempreature, making precise measurement more difficult. MPL researchers have developed a method that can drastically extend the lifespan of these color molecules by freezing the samples at temperatures close to absolute zero. In a complex technical process developed in-house, the PIEZO proteins are shock-frozen without their structure being destroyed in the freezing process. The molecules then have the property of going on and off randomly like little lighthouses. Scientists make use of this effect to determine the exact position of the molecules on the sub-nanometer scale. “The blinking reveals the actual structure of the proteins and how they change shape while the cell is active. This enables us to understand how this PIEZO protein actually works,” explains Hisham Mazal of Prof. Vahid Sandoghdar´s research division.