CRC 1078: Protonation Dynamics in Protein Function

How do proteins function? Which mechanisms are effective in the regulation of processes by proteins? These questions are addressed by molecular life-science research at the borders of biology, chemistry and physics. In doing so, key principles of protein function like the key-and-lock principle in substrate binding were identified. The research in the Collaborative Research Centre aims at a further principle, where complex protein functions are coordinated and facilitated by evolutionary optimised protonation dynamics. In phytochromes of plants and cyanobacteria, a pigment absorbs light and a remote protein domain passes on the light signal. In phytochromes – as in complex proteins in general – various functional sites or domains need to work in a coordinated way. This is facilitated – according to our central working hypothesis – by distinct protonation dynamics. The term “protonation dynamics” includes the local relocation of protons within hydrogen-bonded networks of amino-acid residues and water molecules as well as the directed long-distance proton transfer and associated changes of long-range electrostatic interactions. To address this hypothesis, four specific protein systems were selected, which are particularly well suited to clarify complementary aspects of the hypothesis. The coupling of protonation dynamics to multistage redox reactions is investigated in photosystem II (photosynthetic water oxidation) and cytochrome-c-oxidase (oxygen reduction and proton pumping in respiration). The interrelation between protonation dynamics and conformational changes in light-reception, signal transduction and ion-channel conductance is investigated in channel rhodopsins (light-gated cation channels) and phytochromes (bi-stable photoreceptor controlling kinase activity). It is our goal to understand, by means of these exemplary investigations, the role of protonation dynamics in protein function at a basic physical-chemical level. To achieve this goal we use a combination of new biophysical experiments with molecular simulations and quantum-chemical computations. Albeit the research programme is focussed on basic questions, it could inspire new approaches in energy sciences (light-driven water oxidation, oxygen reduction) and support the development of new tools in medical sciences (knowledge-based customisation of channel rhodopsins for application in neurosciences) and biotechnology (photoreceptors in light-controlled gene expression).

Principal investigators
SZF-1, Leitung Servicezentrum Forschung (Details) (Research Service Centre)

DFG: Sonderforschungsbereich

Duration of project
Start date: 01/2013
End date: 12/2020

Research Areas

Research Areas
Biochemie, Biophysik, (Bio-) physikalische Chemie, Kristallografie, Molekularbiologie, Spektroskopie, Strukturbiologie, Theoretische Physik, Weiche Materie

Last updated on 2022-07-09 at 17:07