Faculty of Engineering
BME Seminar - Erhan Deniz (Goethe University Germany) - September 5, 2019 time:10.00 place:E102
Title: Infrared labels in steady-state and transient vibrational spectroscopy: Detecting conformational changes and vibrational energy transfer in proteins
Erhan Deniz, Katharina B. Eberl, Jan G. Löffler, Georg Wille, Werner Mäntele and Jens Bredenbeck
Institute of Biophysics, Goethe University Frankfurt/Main, Germany
Time and Place: September 5, 2019 @10.00 in E102
Abstract: Infrared (IR) labels provide localized insights into protein structure and dynamics. The thiol (SH) stretching mode of cysteine absorbs around 2550 cm-1 without any other overlapping protein absorption. The precise location and shape of the SH-band depends on the thiol H-bonding environment. We employ these features to monitor structural rearrangements in proteins.
We applied redox difference spectroscopy to pyruvate oxidase from E. coli (EcPOX) – a peripheral redox membrane protein that intermittently binds to the cell membrane where it feeds the respiratory chain with electrons. We identified two cysteines (out of ten) with a distinct SH band-shift upon redox reaction. These thiols sense the redox-induced exposure of the C-terminal membrane binding anchor, even though they are quite remote from the C-terminus.
Non-canonical amino acids (ncAA) can also provide IR signatures spectrally separated from the crowded amide region. We established the azide stretching mode (~ 2100 cm-1) of azidohomoalanine (Aha) as a sensor for vibrational energy, i.e. heat. Together with azulenylalanine – an ultrafast heater – we have a protein-compatible ncAA pair in hand for studying vibrational energy transfer (VET) in peptides and proteins.
VET is an excellent reporter for mechanically coupled amino acids, which might play a key role in dynamic allostery, i.e. allosteric communication without major conformational change. We applied ultrafast pump- probe spectroscopy to tryptophan zippers – short peptides with a stable hairpin structure – and the PDZ3 domain of the PSD95, a paradigm for dynamic allosteric regulation. We observe VET on a picosecond timescale along covalent bonds and non- covalent contacts, e.g. H-bonds. VET timing nicely correlates with the VET pair distance and can currently be resolved up to a distance of 17 Å.
Related Files
NEWS |ALL NEWS
Prof. Pasquale's visit
Prof. Pasquale Daponte from the University of Benevento Sannio, Italy visited our Aerospace Engineering department during the period from 07.03 to 10.03 to discuss
Presentation of Prof. Slawomir Szrama
Prof. Slawomir Szrama visited our university and Aerospace Engineering department during period from 04.03.2024 to 08.03.2024. He gave a talk about "Neural Networks
Life-saving projects
Students of Izmir University of Economics (IUE) took action in response to the increase in natural disasters such as earthquakes, floods and
Technical Trip of The Aerospace Engineering Department to Gaziemir
A technical trip was conducted to the Aviation Sciences laboratories of the Air Force Non-Commissioned Officer Vocational School affiliated with the National
IUE Professor elected as a ‘president’
Prof. Dr. Aydın Akan, Head of the Department of Electrical and Electronics Engineering at Izmir University of Economics (IEU), who was featured
Biomedical Engineering Erasmus Agreement was signed with Universidad Jaume University, Spain
The signing process for the agreement with Universidad Jaume for Biomedical Engineering has been completed. Our students can add this university to
Award-winning helicopters promoted in Azerbaijan
Izmir University of Economics (IUE) students, who managed to receive awards at TEKNOFEST two years in a row with the cargo transport
Electric car presented at TEKNOFEST
The electric car developed by Izmir University of Economics (IUE) students to be exhibited at TEKNOFEST, Turkey's first and only aerospace and