Amyloid Peptide Mixtures : Self-Assembly, Hydrogelation, Nematic Ordering, and Catalysts in Aldol Reactions

Morphological, spectroscopic, and scattering studies of the self-assembly and aggregation of mixtures of [RF]4 and P[RF]4 peptides (where R = arginine; F = phenylalanine; P = proline), in solution and as hydrogels, were performed to obtain information about polymorphism. CD data confirmed a β-sheet...

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Veröffentlicht in:Langmuir : the ACS journal of surfaces and colloids. - 1999. - 36(2020), 11 vom: 24. März, Seite 2767-2774
1. Verfasser: Pelin, Juliane N B D (VerfasserIn)
Weitere Verfasser: Gerbelli, Barbara B, Edwards-Gayle, Charlotte J C, Aguilar, Andrea M, Castelletto, Valeria, Hamley, Ian W, Alves, Wendel A
Format: Online-Aufsatz
Sprache:English
Veröffentlicht: 2020
Zugriff auf das übergeordnete Werk:Langmuir : the ACS journal of surfaces and colloids
Schlagworte:Journal Article Research Support, Non-U.S. Gov't
Beschreibung
Zusammenfassung:Morphological, spectroscopic, and scattering studies of the self-assembly and aggregation of mixtures of [RF]4 and P[RF]4 peptides (where R = arginine; F = phenylalanine; P = proline), in solution and as hydrogels, were performed to obtain information about polymorphism. CD data confirmed a β-sheet secondary structure in aqueous solution, and TEM images revealed nanofibers with diameters of ∼10 nm and micrometer lengths. SAXS curves were fitted using a mass fractal-component and a long cylinder shell form factor for the liquid samples, and only a long cylinder shell form factor for the gels. Increasing the P[RF]4 content in the systems leads to a reduction in cylinder radius and core scattering density, suggesting an increase in packing of the peptide molecules; however, the opposite effect is observed for the gels, where the scattering density is higher in the shell for the systems containing higher P[RF]4 content. These compounds show potential as catalysts in the asymmetric aldol reactions, with cyclohexanone and p-nitrobenzaldehyde in aqueous media. A moderate conversion (36.9%) and a good stereoselectivity (69:31) were observed for the system containing only [RF]4. With increasing P[RF]4 content, a considerable decrease of the conversion was observed, suggesting differences in the self-assembly and packing factor. Rheological measurements were performed to determine the shear moduli for the soft gels
Beschreibung:Date Completed 30.07.2020
Date Revised 28.03.2024
published: Print-Electronic
Citation Status PubMed-not-MEDLINE
ISSN:1520-5827
DOI:10.1021/acs.langmuir.0c00198