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Updated: Apr 19, 2026

Molecular Spring Constant Analysis by Biomembrane Force Probe Spectroscopy
Published on: November 20, 2021
Methods to determine the pressure dependence of the molecular order parameter in (bio)macromolecular fibres
Arthur Markus Anton1, Christof Gutsche, Wilhelm Kossack
1Universität Leipzig, Fakultät für Physik und Geowissenschaften, Institut für Experimentelle Physik I, Abteilung Molekülphysik, Linnéstraße 5, D-04103 Leipzig, Germany. anton@physik.uni-leipzig.de.
Abstract:
The experimental realization and an algorithm for analysing the pressure dependence of the molecular order parameter of specific structural moieties in (bio)macromolecular fibres are described. By employing a diamond anvil cell (DAC) the polarization-dependent IR-transmission and in parallel, using an integrated microscope, the macroscopic orientation of the fibres is determined. This enables one to separate between order and disorder at macroscopic and microscopic scales. Using the example of spider silk the pressure dependence of the molecular order parameter of alanine groups being located within nano-crystalline building blocks is deduced and found to decrease reversibly by 0.01 GPa(-1) when varying the external hydrostatic pressure between 0 and 3 GPa.
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