Figure 6.

UVRR spectra of beta hairpin peptides. Samples: Peptide J (I) in the absence (A, green) or presence (B, purple) of equimolar ZnCl₂; Peptide P (II) in the absence (A, blue) or presence (B, orange) of equimolar ZnCl₂; Peptide J/F (III) in the absence (A, black) or presence (B, gold) of equimolar ZnCl₂. The peptide concentration was 1 mM, and the samples contained equimolar ZnCl₂ where noted. The buffer contained 5 mM HEPES, pD 7.5. Sample was recirculated using a peristaltic pump to prevent UV damage. Laser wavelength, 244 nm; laser power, 3.4 mW; scan time, 120 s; accumulations, 4. Data were averaged from at least two independent measurements (using at least two 1 mL samples). Tick marks denote 200 intensity units.