Dr. Stephan G. Zech from the Max Volmer Laboratory for Biophysical Chemistry and Biochemistry at the Technical University of Berlin is awarded the Schering Prize 1999 for his research on “Pulsed and transient electron paramagnetic resonance spectroscopy on light induced radical pairs in photosynthetic reaction centers”.

Pulsed and transient electron paramagnetic resonance spectroscopy on light induced radical pairs in photosynthetic reaction centers

Through the process of photosynthesis, plants convert the energy of sunlight into chemically usable forms. Thereby, carbohydrates are produced as source for food of all higher organisms and oxygen is released into the atmosphere. Furthermore, the biomass produced by photosynthesis forms the basis for fossil fuels like coal, mineral oil and natural gas.

For the primary processes of photosynthesis nature uses large proteins embedded into a cell membrane. The structure of these proteins is not known yet in detail. Through the energy of sunlight, a so-called electron transfer occurs within these proteins. That means, an electron is advanced over different molecules from one side of the photosynthetic membrane to the other, forming a electric potential across the membrane.

The goal of my work was it to determine the distance between some of the molecules involved. With the aid of a new technique based on pulsed Electron Spin Resonance, these distances could be measured very precisely. The results were important for a better understanding of the structure and function of these membrane proteins.