Heavy metal ion hydrogelation of a self-assembling peptide via cysteinyl chelationElectronic supplementary information (ESI) available. See DOI: 10.1039/c1jm14418a

Hydrogel materials are finding use in heavy metal ion detection and remediation. MBHP is a twenty-residue peptide capable of undergoing hydrogelation in response to heavy metal ion binding. The unstructured peptide binds monomethylarsonous acid, Pb 2+ , Zn 2+ , Cd 2+ or Hg 2+ and subsequently folds into an amphiphilic -hairpin that rapidly self-assembles into a -sheet rich fibrillar network as shown by CD spectroscopy and transmission electron microscopy. LCMS shows that MBHP binds metal ions with a 1:1 stoichiometry. Oscillatory rheology indicates that moderately rigid hydrogels are formed as a result of metal ion binding, peptide folding and ultimate self-assembly with storage moduli (G) ranging from 10004000 Pa. MBHP is a de novo designed peptide that undergoes self-assembly leading to hydrogelation in response to heavy metal ion binding.