Eur. Phys. J. E (2013) 36: 111
https://doi.org/10.1140/epje/i2013-13111-3

Regular Article

Self-assembly and gelation properties of glycine/leucine Fmoc-dipeptides

¹ School of Materials, The University of Manchester, Grosvenor Street, M1 7HS, Manchester, UK
² Manchester Institute of Biotechnology (MIB), The University of Manchester, 131 Princess Street, M1 7DN, Manchester, UK
³ WestCHEM, Department of Pure & Applied Chemistry, University of Strathclyde, Thomas Graham Building, 295 Cathedral Street, G1 1XL, Glasgow, UK

^* e-mail: a.saiani@manchester.ac.uk

Received: 28 March 2013
Accepted: 5 September 2013
Published online: 3 October 2013

Abstract

Self-assembly of aromatic peptide amphiphiles is known to be driven by a combination of π-π stacking of the aromatic moieties and hydrogen bonding between the peptide backbones, with possible stabilisation from the amino acid side chains. Phenylalanine-based Fmoc-dipeptides have previously been reported for their characteristic apparent pK_a transitions, which were shown to coincide with significant structural and morphological changes that were peptide sequence dependent. Here, phenylalanine was replaced by leucine and the effect on the self-assembling behaviour of Fmoc-dipeptides was measured using potentiometry, fluorescence and infrared spectroscopy, transmission electron microscopy, X-ray scattering and shear rheometry. This study provides additional cues towards the elucidation of the sequence-structure relationship in self-assembling aromatic peptide amphiphiles.