CD spectra of diyne-stapled BCL9 24-mers versus unstapled linear BCL9 24-mers. All peptides were dissolved in PBS, pH 7.4, to a final concentration of 40 μM. 3 baseline scans of buffer were taken and averaged at T=25°C, followed by 5 scans of each peptide. These spectra were averaged, baseline-subtracted from the averaged blank scans, and converted to mean residue ellipticity to plot against wavelength. The percent helicity of each peptide was calculated based on [θ]222/[θ]max. [θ]max was calculated according to the formula: [θ]max=−39000(1–3/n), where n is the number of amide bonds.