Phase Separation in Supramolecular Hydrogels Based on Peptide Self-Assembly from Enzyme-coated Nanoparticles.
Fiche publication
Date publication
juillet 2019
Journal
Langmuir : the ACS journal of surfaces and colloids
Auteurs
Membres identifiés du Cancéropôle Est :
Pr SCHAAF Pierre, Dr SCHMUTZ Marc
Tous les auteurs :
Criado-Gonzalez M, Rodon Fores J, Carvalho A, Blanck C, Schmutz M, Kocgozlu L, Schaaf P, Jierry L, Boulmedais F
Lien Pubmed
Résumé
Spatial localization of biocatalysts, such as enzymes, has recently proven to be an effective process to direct supramolecular self-assemblies in a spatiotemporal way. In this work, silica nanoparticles functionalized covalently by alkaline phosphatase (NPs@AP) induce the localized growth of self-assembled peptide nanofibers from NPs by dephosphorylation of Fmoc-FFpY peptides (Fmoc: Fluorenylmethyloxycarbonyl; F: phenylalanine; Y: tyrosine; p: phosphate group). The fibrillary nanoarchitecture around NPs@AP underpins a homogeneous hydrogel which unexpectedly undergoes a macroscopic shape change over time. This macroscopic change is due to a phase separation leading to a dense phase (in NPs and nanofibers) in the center of the vial and surrounded by a dilute one which still contains NPs and peptides self-assemblies. We thus hypothesize that the phase separation is not a syneresis process. Such a change is only observed when the enzymes are localized on the NPs. The dense phase contracts with time until reaching a constant volume after several days. For a given phosphorylated peptide concentration, the dense phase contracts faster when NPs@AP concentration is increased. For a given NPs@AP concentration, it condenses faster when the peptide concentration increases. We hypothesize that the appearance of a dense phase is not only due to attractive interactions between NPs@AP but also to the strong interaction of self-assembled peptide nanofibers with the enzymes, covalently fixed on the NPs.
Référence
Langmuir. 2019 Jul 23;: