TY - JOUR A1 - Chowdhary, S. A1 - Schmidt, R. F. A1 - Sahoo, A. K. A1 - tom Dieck, T. A1 - Hohmann, T. A1 - Schade, B. A1 - Brademann-Jock, Kerstin A1 - Thünemann, Andreas A1 - Netz, R. R. A1 - Gradzielski, M. A1 - Koksch, B. T1 - Rational design of amphiphilic fluorinated peptides: evaluation of self-assembly properties and hydrogel formation JF - Nanoscale N2 - Advanced peptide-based nanomaterials composed of self-assembling peptides (SAPs) are of emerging interest in pharmaceutical and biomedical applications. The introduction of fluorine into peptides, in fact, offers unique opportunities to tune their biophysical properties and intermolecular interactions. In particular, the degree of fluorination plays a crucial role in peptide engineering as it can be used to control the characteristics of fluorine-specific interactions and, thus, peptide conformation and self-assembly. Here, we designed and explored a series of amphipathic peptides by incorporating the fluorinated amino acids (2S)-4-monofluoroethylglycine (MfeGly), (2S)-4,4-difluoroethylglycine (DfeGly) and (2S)-4,4,4-trifluoroethylglycine (TfeGly) as hydrophobic components. This approach enabled studying the impact of fluorination on secondary structure formation and peptide self-assembly on a systematic basis. We show that the interplay between polarity and hydrophobicity, both induced differentially by varying degrees of side chain fluorination, does affect peptide folding significantly. A greater degree of fluorination promotes peptide fibrillation and subsequent formation of physical hydrogels in physiological conditions. Molecular simulations revealed the key role played by electrostatically driven intra-chain and inter-chain contact pairs that are modulated by side chain fluorination and give insights into the different self-organization behaviour of selected peptides. Our study provides a systematic report about the distinct features of fluorinated oligomeric peptides with potential applications as peptide-based biomaterials. KW - Small-angle X-ray scattering KW - SAXS KW - Amyloid PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-553504 DO - https://doi.org/10.1039/D2NR01648F SN - 2040-3364 VL - 14 IS - 28 SP - 10176 EP - 10189 PB - Royal Society of Chemistry AN - OPUS4-55350 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Beckmann, Jörg A1 - Marchetti, B. A1 - von Chrzanowski, Lars S. A1 - Ritter, E. A1 - Puskar, L. A1 - Aziz, E. F. A1 - Schade, U. T1 - Optical constants of harmful and highly energetic liquids for application to THz screening systems JF - IEEE Transactions on Terahertz Science and Technology N2 - The far-infrared (IR) optical constants of a set of hazardous and flammable liquids have been obtained by means of spectroscopic ellipsometry in attenuated total reflection configuration over a broad spectral range. Such liquids recently became of considerable concern for transportation security measures worldwide. Their optical identification at check-in gates can only become possible if the characteristic spectra are already known. The refractive indices and the extinction coefficients reported here contribute to a spectroscopic data base in the far-IR and terahertz (THz) spectral regions and may support modeling the performance of THz screening systems on liquids for airports and other security sensitive areas. Examples of several container material/liquid systems are discussed. From the measured optical constants typical THz waveforms are calculated and discussed. KW - liquids material characterization KW - Ellipsometry KW - FT-IR spectroscopy KW - THz time-domain spectroscopy (THz-TDS) PY - 2016 DO - https://doi.org/10.1109/TTHZ.2016.2547319 SN - 2156-342X VL - 2016 / Vol. PP IS - 99 SP - 1 EP - 12 PB - IEEE - Inst. Electrical Electronics Engineers Inc CY - New York, NY, USA AN - OPUS4-36366 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -