Figure 5.

Interactions during glucagon fibrillation monitored by amide HDX-MS. A 5 min pulse labeling with deuterium was carried out for fibrillating glucagon at regular intervals (0–480 min). The deuterium uptake was measured by MS analysis following online pepsin digestion (A) Percent deuterium uptake for peptides 1–6, 1–9, 10–21, and 22–29 as a function of time of fibrillation. Lines represent fits to monoexponential decay; see text for details (n = 3, mean ± SD). (B) t₅₀ values for the decrease in deuterium incorporation in the nine glucagon fragments (n = 3 ± SE).