SKM 2023 – wissenschaftliches Programm
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BP: Fachverband Biologische Physik
BP 21: Bioimaging
BP 21.2: Vortrag
Donnerstag, 30. März 2023, 09:45–10:00, BAR Schö
Spectral and nanolocal discrimination of crosslinked from single fibrillar actin using mid-IR photoinduced force microscopy (PiF-IR) — Jesvin Joseph1,2, Dijo Moonnukandathil Joseph1,2, Lukas Spantzel2,3, Katharina Reglinski1,2, Christoph Krafft1,2, Christian Eggeling1,2, Rainer Heintzmann1,2, Michael Börsch2,3, and •Daniela Täuber1,2 — 1Leibniz Institute of Photonic Technology, Jena — 2Friedrich Schiller University Jena — 3Jena University Hospital, Jena, Germany
Fibrillar actin is one of the major structural components in cells. Consequently, pathogenic alterations in cell functionality may be revealed by monitoring the re-arrangement of F-actin. However, discriminating protein aggregation in the range below 10 nm is challenging even by high resolution fluorescence microscopy. This gap can be addressed by recently developed mid-IR photo-induced force microscopy (PiF-IR). PiF-IR spectra obtained from fibrillar and monomeric actin match the corresponding FTIR spectra. The high spectral resolution of PiF-IR provides simplified access to IR spectroscopic signatures from secondary protein structure. The intensity of bands at 1655 cm-1 and 1685 cm-1 associated to α-helices and intermolecular β-sheets, respectively, varied within the scan image. Furthermore, PiF-IR hyperspectra obtained form single fibrillar actin appear more homogeneous than those from cross-linked F-actin. These first results are very promising for using PiF-IR to discriminate F-actin structures to study pathogenic alterations in cells and tissue ex vivo.