Fig. 3. Amino acid sequences of peptides 6–11 (from N- to C-terminus). Chromatograms showing the oxidation of 6–11 (10 μM) in 0.2 mM GSSG (100 mM phosphate buffer, pH 7.4) (black line: before oxidation; red line: 2 h after oxidative folding). Topological drawings of the expected folds were given in bottom panels (red lines denote disulfide bonds; amino acid sequences can be read in a counter-clockwise direction). The disulfide connectivity of peaks a and b shown in the chromatograms (by products): 6-a = (1–6, 2–5, 3–4), 6-b = (1–4, 2–3, 5–6); 8-a = (1–5, 2–3, 4–6), 8-b = (1–4, 2–6, 3–5); 9-a = (1–5, 2–4, 3–6), 9-b = (1–2, 3–5, 4–6); 10-a = (1–6, 2–3, 4–5); 11-a = (1–4, 2–6, 3–5), 11-b = (1–3, 2–5, 4–6). Disulfide pairings were established by tryptic digestion HPLC and mass spectrometry (Fig. S15–S36†). Of note, a pair of conformers formed from the folding of 9, which have identical disulfide connectivity (1–6, 2–4, 3–5).