Université de Strasbourg

Petra Hellwig


Complex Matter Chemistry (CMC), University of Strasbourg and CNRS

Petra Hellwig, USIAS Fellow 2018

Professor Petra Hellwig received her PhD in 1998 from the University of Erlangen (Germany) under the supervision of Werner Mäntele. From 1998 to 1999 and from 2001 to 2005 she was a researcher at the Institute of Biophysics at the University of Frankfurt and, from 1999 to 2001, at the University of Illinois Urbana-Champaign (USA). After her habilitation in 2002, she was appointed professor in 2005 at the University of Strasbourg.

She is a professor in the Faculty of Chemistry and directs the research unit Chemistry of Complex Matter as well as the Laboratory of Bioelectrochemistry and Spectroscopy. She was awarded a ANR (French National Research Agency) Junior Chair of Excellence  in 2007 and was junior member of the Institut Universitaire de France (IUF) from 2010-2015.

With her interdisciplinary expertise in biophysics and physical chemistry she uses vibrational spectroscopy and bioelectrochemistry for the study of the reaction mechanism of membrane proteins and their principle(s) of operation. Her research focuses on enzymes from the respiratory chain and as membrane transporters.

Project - The reaction mechanism of proteins studied in nanopores

November 2018 – October 2020

Membrane proteins are essential to crucial processes such as membrane transport, signaling, respiration and photosynthesis. It is estimated that, in the next century, 80 to 90% of ‘druggable’ targets are membrane proteins. Their contributions to the energy state of the cell are ruled by their conformation and position and reactivity of specific residues in response to the electrochemical ion gradients that are composed of an electrical and a concentration component. A common motif in proton translocating membrane proteins is several well defined acid/base pair(s) with specifically shifted pK values, a topic that is increasingly at the focus of current frontier research.

Here we develop an approach allowing the in situ identification of protonation/de-protonation of specific residues in response to the conformation of the membrane protein and to the membrane potential by infrared spectroscopy, more specifically the lactose permease. Vibrational spectroscopies provide molecular fingerprints of the catalytic reaction of a protein. By combining infrared spectroscopies and solid-state plasmonic nanostructures with an excitation at wavelengths that are specific for the signature of protonated acidic residues, protein backbone and the overall hydrogen bonding network in the protein, we aim to monitor the reactions of the protein during catalysis. The individual nanoreactors will be coupled to electrochemistry in order to mimic the natural potential of the membrane, thus allowing us to perform a label free detection of the catalytic reaction and the conformational control within crucial membrane proteins. 

Investissements d'Avenir