Berlin 2024 – scientific programme
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BP: Fachverband Biologische Physik
BP 18: Biomaterials and Biopolymers (joint session BP/CPP)
BP 18.2: Talk
Wednesday, March 20, 2024, 10:00–10:15, H 1028
Understanding the molecular determinants of chitin-protein interactions in the arthropod cuticle - a single-molecule approach — •Ayesha Talib1,2, Yael Politi2, and Kerstin G. Blank1,3 — 1Max Planck Institute of Colloids and Interfaces, Mechano(bio)chemistry, Am Mühlenberg 1, 14476 Potsdam, Germany — 2Technische Universität Dresden, CMCB, B CUBE, Tatzberg 41, 01307 Dresden, Germany — 3Johannes Kepler Universität, Institute of Experimental Physics, Altenberger Straße 69, 4040 Linz, Austria
In the cuticle of arthropods, structural proteins and chitin fibers form a composite material with anisotropic mechanical properties. The molecular parameters that define the chitin-protein interaction are largely unknown. To answer the fundamental question of what controls cuticle mechanical properties, a molecular strategy is employed that integrates protein engineering with single-molecule force spectroscopy. Chitin binding domains (CBDs) from the spider Cupiennius salei have been identified and expressed recombinantly to compare the strength of the protein-chitin interaction. For CBD present in all spider tissues, we investigated three overlapping consensus motifs RR-1, RR-2 and CB-4. Pull-down assays and single-molecule force spectroscopy suggest that the RR-1 motif does not bind to chitin, whereas similar binding strength is observed for the RR-2 and CB-4. We observe a fast dissociation rate, suggesting that CBDs facilitate energy dissipation upon deformation. Our ultimate goal is to correlate molecular properties with the mechanical function of the composite and to synthesize artificial analogues with tunable mechanical properties.
Keywords: Arthropod cuticle; Cuticle proteins; Chitin binding domains; Single-molecule force spectroscopy