Fig. 2.

H/D exchange heat map of the relative deuterium incorporation for caspase-6 maturation-state variants. For each peptic peptide from the caspase-6 maturation-state variants, the percentage relative deuterium level for each H/D exchange incubation time (minutes: 0.17, 1, 10, 60, and 120) is mapped onto the corresponding linear sequence of caspase-6. The percentage relative deuterium incorporation is calculated by dividing the observed deuterium uptake by the theoretical maximum deuterium uptake for each peptide. The H/DX-MS experiments followed all observed peptides and cover 90.8–92.1% of the combined linear sequences. Peptic peptides with no H/D exchange data at a given incubation time or regions absent in various constructs are colored white. Secondary structural elements are depicted above the primary sequence. The asterisk designates the D to A substitution at the indicated proteolytic cleavage site, rendering that site uncleavable. The percentage relative deuterium level of each peptic peptide represents the average values of duplicate experiments performed on 2 separate days. ^§This H/DX-MS dataset has been reported in ref. 36.