Figure 2. Characterization of the β-hairpin tertiary structures and a kinked bulge-like motif signature by CD spectroscopy.

(A) Synthetic Library of CDR-H3 peptide mimics; Synthetic yields and thermodynamic folding properties of β-hairpins obtained by CD analysis are reported. (B) Overlay of CD spectra obtained at 0 °C between a regular benchmark hairpin 1l and the novel bulge-like hairpins 1d-k: typical exciton couplet for a W/W pair at the hairpin strap termini (228 ± 1 nm) and a novel CD band attributed to the bulge-like structure (202 ± 2 nm). (C) Representative thermal denaturation of hairpin 1d monitored at both 202 and 228 nm. (D) Comparison between individual best-fitted melting curves for selected hairpins 1d,h,k based on a two-state model (global hairpin fraying vs local kinked motif denaturation in solid and dashed lines respectively).