Fig. 3

CD analysis and rheology data with variable [Cu(II)] showing that the ratio of F9 4ʹPyA peptide and Cu(II) is 2 to 1. A Correlation of mean residue ellipticity (MRE) at 220 nm and copper concentration. Final concentration of peptide is 100 µM; buffer 5 mM HEPES, pH 8; pathlength of cuvettes 1 mm. Samples were prepared by incubating peptide, Cu(II) in buffer at 37 °C for 3 h. For full CD spectra see Additional file 1: Fig. S5; B Evolution of storage modulus over time. Gels were prepared by dissolving 2 wt% F9 4ʹPyA and Cu(II) in water and then equal volume of the buffer (75 µL; 100 mM HEPES, pH 8) was added