FIGURE 9.

Degradation of E14Q-HD5 by elastase and chymotrypsin at 30 min and 2 h. Conditions for HPLC analysis were the same as described in the legends for Figs. 4, 6, and 7. For chymotrypsin, cleaved E14Q-HD5 differed from intact E14Q-HD5 by +18 Da in molecular mass, attributable to the cleavage of the Tyr²⁷–Arg²⁸ peptide bond. The minor peak eluted before E14Q-HD5 after 2 h of incubation with the enzyme contained doubly and triply cleaved peptides as indicated by mass spectrometric analysis. mAU, milliabsorbance units.