Real‐Time In‐Situ Monitoring of a Tunable Pentapeptide Gel–Crystal Transition. (18th September 2019)

• Record Type: Journal Article
• Authors: Guterman, Tom; Levin, Maayan; Kolusheva, Sofiya; Levy, Davide; Noor, Nadav; Roichman, Yael; Gazit, Ehud
• Is Part Of: Angewandte Chemie. Volume 131:Number 44(2019)
• Page Start: 16016
• Page End: 16022
• Publication Date: 2019-09-18
• Subjects: Gele -- Mikroskopie -- Peptide -- Phasenumwandlung -- Selbstorganisation; Chemistry -- Periodicals; 540
• DOI: 10.1002/ange.201907971
• Languages: English
• ISSNs: 0044-8249

Abstract

Abstract: Supramolecular gels often become destabilized by the transition of the gelator into a more stable crystalline phase, but often the long timescale and sporadic localization of the crystalline phase preclude a persistent observation of this process. We present a pentapeptide gel–crystal phase transition amenable for continuous visualization and quantification by common microscopic methods, allowing the extraction of kinetics and visualization of the dynamics of the transition. Using optical microscopy and microrheology, we show that the transition is a sporadic event in which gel dissolution is associated with microcrystalline growth that follows a sigmoidal rate profile. The two phases are based on β‐sheets of similar yet distinct configuration. We also demonstrate that the transition kinetics and crystal morphology can be modulated by extrinsic factors, including temperature, solvent composition, and mechanical perturbation. This work introduces an accessible model system and methodology for studying phase transitions in supramolecular gels. Abstract : Ungewöhnlicher Phasenprüfer : Ein Pentapeptidsystem für die Untersuchung von Gel‐Kristall‐Phasenumwandlungen in supramolekularen Gelen wird vorgestellt. Das System ermöglicht eine durchgängige Messung der Kinetik und die Visualisierung der Dynamik des Gel‐destabilisierenden Phasenumwandlungsprozesses in situ mit nicht‐destruktiven Mikroskopiemethoden.