Figure 2.
Effect of pH on (a) secondary structure and (b) bulk adhesion strength of ELP[KEY4-48]. (a) CD spectrometry was performed on protein solutions at pH 3, 4.5, 9 and 10.5. Secondary structure did not vary significantly with pH. Negative peaks at 198 nm and 220 nm indicate unstructured and β-II turn secondary structure, respectively. (b) Bulk adhesion testing between aluminium substrates was performed with protein at pH 3, 4.5, 7, 9, 10.5 and 12. Adhesion strengths did not demonstrate significant variation with pH when assessed by one-way ANOVA followed by Tukey's HSD post hoc analysis.