Sequence/structure relationships in aromatic dipeptide hydrogels formed under thermodynamic control by enzyme-assisted self-assemblyElectronic supplementary information (ESI) available: CryoTEM images, rheological time studies of gel formation, further fluorescence and WAXS data. See DOI: 10.1039/c2sm25224d

• Main Authors: Hughes, Meghan, Frederix, Pim W. J. M, Raeburn, Jaclyn, Birchall, Louise S, Sadownik, Jan, Coomer, Fiona C, Lin, I-Hsin, Cussen, Edmund J, Hunt, Neil T, Tuttle, Tell, Webb, Simon J, Adams, Dave J, Ulijn, Rein V
• Format: Article
• Language: English
• ISSN: 1744-683X; 1744-6848
• DOI: 10.1039/c2sm25224d

Self-assembled supramolecular structures of peptide derivatives often reflect a kinetically trapped state rather than the thermodynamically most favoured structure, which presents a challenge when trying to elucidate the molecular design rules for these systems. In this article we use thermodynamically controlled self-assembly, driven by enzymatic condensation of amino acid derivatives, to elucidate chemical composition/nanostructure relationships for four closely related Fmoc-dipeptide-methyl esters which form hydrogels; SF, SL, TF and TL. We demonstrate that each of the four systems self-assemble to form extended arrays of β-sheets which interlock via π-stacking of Fmoc-moieties, yet with subtle differences in molecular organisation as supported by rheology, fluorescence emission spectroscopy, infrared spectroscopy, X-ray diffraction analysis and molecular mechanics minimisation. The influence of small chemical changes in supramolecular assembly of Fmoc-peptide esters is systematically investigated using enzymatic condensation of amino acid precursors.