Partner 5. J.W. Goethe Universität Frankfurt (UFRANK.BIOPHYS)
Institut für Biophysik
Theodor-Stern Kai, Haus 74
60590 Frankfurt am Main - Germany

Scientific team

Name	Position		Task
Werner Mäntele	full professor, chair		team leader
Andreas Barth	assistant professor		enzyme-substrate interactions, time-resolved IR
Christian Zscherp	post-doctoral fellow		FTIR-spectroscopy of proteins, protein folding
Petra Hellwig	post-doctoral fellow		electrochemistry & spectroscopy of respiratory enzymes
Michaela Ritter	PhD student		coupling of electron & proton transfer in bc complex
Oliver Klein	PhD student		ion transport across membranes, ATR-IR spectroscopy
Martha Gomez	PhD student		near-IR spectroscopy for biomedical diagnostics
Tatiana Nazarowa	PhD student		laser-induced T jump, protein folding studies

Subcontractor partner for Biomedical Diagnostics:
Elté Diagnostic GmbH, Prof. v. Lilienfeld Toal, Med. Klinik, Kreiskrankenhaus Gelnhausen, 63571 Gelnhausen

Objectives
The group at the Johann Wolfgang Goethe-Universität Frankfurt/Main is active in the characterisation of enzyme function and reaction mechanisms. Examples of the target enzymes for this study are terminal oxidases, ATPases, photosynthetic systems as well as proteins from biological signal transfer chains. Most proteins are of bacterial origin, thus facilitating production and isolation. Although there exist high-resolution structures for some of the proteins investigated, their functional properties and reaction mechanisms are still unclear. The instrumentation used for the study includes several Fourier transform IR spectrophotometers, some of them already used for millisecond studies and one of them now extended for nanosecond studies. These techniques are complemented by a prototype IR photometer using several tunable mid-IR lasers which altogether cover the spectral range from 2000 cm-1 - 1200 cm-1. For the rapid and quantitative initiation of enzyme reactions with photoinduced reactions, we are equipped with ND-YAG pulsed lasers with harmonic generation (1064, 532, 355, 266 nm) and a Raman shifter to generate near IR pulses for rapid temperature jump. This equipment is complemented by routine analytical UV/VIS spectroscopy (steady-state and time-resolved), fluorimetry, electrochemistry , etc, as well as with biochemical and chemical techniques. In a local collaboration with a clinical partner and a company working on medical equipment, the use of spectroscopic techniques in particular near-IR spectroscopy, for biomedical analysis, will be developed.

Workplan
UFRANK.BIOPHYS will mostly contribute to WP-1 with 75 person-months. For the functional investigation of proteins and enzymes modern IR spectroscopic techniques will be used, such as Fourier transform infrared (FTIR) spectroscopy, or tunable lead salt IR diode lasers, which provide a sensitivity high enough to detect contributions of individual bonds to the vibrational spectrum of the entire protein. Time-resolved studies, from nanoseconds to seconds, will also be performed, allowing to monitor the absorbance of these bonds in real time in the course of a reaction. For the assignment of IR bands, strategies like isotope replacement, chemical modifications, and (in cooperation with a local molecular genetics group) site-directed mutagenesis will be used. The infrared difference spectra thus gained provide evidence for distinct conformational changes in the processes of electron transfer, and form a basis for the understanding of reaction mechanisms in some of the enzymes studied.