TY - CONF A1 - Hahn, Marc Benjamin T1 - What can we learn from polymer degradation by radiation? N2 - It is discussed what can be learned from polymer degradation, especially of biopolymers such as DNA and proteins. Synergetci effects of combining methods for structural and chemical analysis as well as Monte-Carlo simulations are presented. T2 - Material Strategy CY - Beelitz, Germany DA - 12.10.2022 KW - Polymer KW - Polymer degradation KW - DNA KW - Protein KW - XPS KW - ESEM KW - Raman KW - MCS KW - Monte-Carlo Simulations PY - 2022 AN - OPUS4-56123 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hahn, Marc Benjamin T1 - Data processing and nonlinear curve Fitting with fityk N2 - A brief introduction into fityk is given. The introduction is followed by a pratical session. Fityk is a versatile data processing tool for nonlinear curve fitting. T2 - AFM Data analysis seminar CY - Online meeting DA - 23.02.2021 KW - Fityk KW - Curve fitting KW - Analysis KW - Raman KW - IR KW - XPS PY - 2021 AN - OPUS4-52154 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Solomun, Tihomir A1 - Cordsmeier, Leo A1 - Hallier, Dorothea C. A1 - Seitz, Harald A1 - Hahn, Marc Benjamin T1 - Interaction of a Dimeric Single-Stranded DNA-Binding Protein (G5P) with DNA Hairpins. A Molecular Beacon Study N2 - Gene-V protein (G5P/GVP) is a single-stranded (ss)DNA-binding protein (SBP) of bacteriophage f1 that is required for DNA synthesis and repair. In solution, it exists as a dimer that binds two antiparallel ssDNA strands with high affinity in a cooperative manner, forming a left-handed helical protein–DNA filament. Here, we report on fluorescence studies of the interaction of G5P with different DNA oligonucleotides having a hairpin structure (molecular beacon, MB) with a seven base-pair stem (dT24-stem7, dT18-stem7), as well as with DNA oligonucleotides (dT38, dT24) without a defined secondary structure. All oligonucleotides were end-labeled with a Cy3-fluorophore and a BHQ2-quencher. In the case of DNA oligonucleotides without a secondary structure, an almost complete quenching of their strong fluorescence (with about 5% residual intensity) was observed upon the binding of G5P. This implies an exact alignment of the ends of the DNA strand(s) in the saturated complex. The interaction of the DNA hairpins with G5P led to the unzipping of the base-paired stem, as revealed by fluorescence measurements, fluorescence microfluidic mixing experiments, and electrophoretic mobility shift assay data. Importantly, the disruption of ssDNA’s secondary structure agrees with the behavior of other single-stranded DNA-binding proteins (SBPs). In addition, substantial protein-induced fluorescence enhancement (PIFE) of the Cy3-fluorescence was observed. KW - DNA KW - Protein KW - ssDNA KW - Fluorescence KW - Raman KW - G5P KW - Hairpin KW - Molecular beacon KW - Quencher KW - Amino Acids KW - SBP KW - SSB KW - Cy3 KW - PIFE KW - Protein-induced fluorescence enhancement KW - Protein–DNA filament KW - Single-stranded DNA-binding protein KW - Bacteriophage f1 KW - Oligonucleotides PY - 2023 U6 - https://doi.org/10.1021/acs.jpcb.3c03669 SN - 1520-6106 VL - 127 IS - 38 SP - 8131 EP - 8138 PB - ACS Publications AN - OPUS4-58295 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -