Cyanine Dye Coupling Mediates Self‐assembly of a pH Sensitive Peptide into Novel 3D Architectures. Issue 48 (26th October 2022)

• Record Type: Journal Article
• Authors: Fernandes, Rita; Chowdhary, Suvrat; Mikula, Natalia; Saleh, Noureldin; Kanevche, Katerina; Berlepsch, Hans v.; Hosogi, Naoki; Heberle, Joachim; Weber, Marcus; Böttcher, Christoph; Koksch, Beate
• Is Part Of: Angewandte Chemie international edition. Volume 61:Issue 48(2022)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2022-10-26
• Subjects: Chromophore Assembly -- Cyanines -- De Novo Peptide -- Electron Microscopy -- H-Aggregates; Chemistry -- Periodicals; 540
• DOI: 10.1002/anie.202208647
• Languages: English
• ISSNs: 1433-7851

Abstract

Abstract: Synthetic multichromophore systems are of great importance in artificial light harvesting devices, organic optoelectronics, tumor imaging and therapy. Here, we introduce a promising strategy for the construction of self‐assembled peptide templated dye stacks based on coupling of a de novo designed pH sensitive peptide with a cyanine dye Cy5 at its N‐terminus. Microscopic techniques, in particular cryogenic TEM (cryo‐TEM) and cryo‐electron tomography technique (cryo‐ET), reveal two types of highly ordered three‐dimensional assembly structures on the micrometer scale. Unbranched compact layered rods are observed at pH 7.4 and two‐dimensional membrane‐like assemblies at pH 3.4, both species displaying spectral features of H‐aggregates. Molecular dynamics simulations reveal that the coupling of Cy5 moieties promotes the formation of both ultrastructures, whereas the protonation states of acidic and basic amino acid side chains dictates their ultimate three‐dimensional organization. Abstract : A conjugated Cy5 dye‐peptide system reveals the formation of two novel and structurally distinct supramolecular assemblies with photo‐physical characteristics of H‐type dimers or tetramers, respectively. The molecular ultrastructures are triggered by the complementary interplay of mutual chromophore coupling and pH induced changes in the peptide charge pattern.