16.02.2022
The far-infrared spectroscopy in the so-called terahertz (THz) spectral range (wavenumbers from 40 cm-1 to 400 cm-1) allows for the non-invasive probing of biomolecular interactions due to the detection of vibrational spectroscopic fingerprints. In the THz spectral window vibrational modes of intramolecular hydrogen (H)-bonds can be detected. H-bonds are responsible contributors for the binding events and reactions of protein molecules among each other. The spectroscopic fingerprints were exploited here for probing the inter- and intramolecular structural changes (conformational changes) of biomolecules, as well as were implemented for the detection of temperature-dependent fine-structural re-organisations.
The Metrology Light Source, the electron storage ring of PTB, is a broad-band source that is well-suited for its implementation in the THz spectral window. The far-infrared spectroscopy has been successfully applied for the characterisation of antimicrobial α-helical peptides, which undergo different folding-mediated interactions with the specific phospholipid-based membrane type. It was demonstrated that during peptide-membrane interaction, a three-dimensional structure in the peptide was formed. In consequence, the membrane structure is altered, leading to pore formation or embedment of peptides, until lesion of the membrane itself. Antimicrobial peptides are important components of the innate immune system (effector molecules) that preferentially attack bacterial membranes by forming and assembling into cell pores through conformational changes, leading to membrane lesions until cell death. This makes them potential alternative drug candidates for conventional antibiotics.
The research based on the project HLT10 ‘Metrology for biomolecular origin of disease‘ of the European Metrology Research Programme EMRP, was performed in collaboration with ELETTRA Synchrotron Trieste (ITA), the National Physical Laboratory (GBR) and the University of Potsdam.
Publication:
A. Hornemann, D. M. Eichert, A. Hoehl, B. Tiersch, G. Ulm, M. G. Ryadnov, and B. Beckhoff, "Investigating Membrane-Mediated Antimicrobial Peptide Interactions with Synchrotron Radiation Far-Infrared Spectroscopy," ChemPhysChem 2022, e202100815(1 of 11).
DOI: https://doi.org/10.1002/cphc.202100815
Contact:
A. Hornemann, 7.11, E-Mail: 
Andrea.Hornemann(at)ptb.de
B. Beckhoff, 7.24, E-Mail: Burkhard.Beckhoff(at)ptb.de