Figure 3.

MALDI-MS analysis of TSLP following incubation with tryptase under strictly controlled conditions (E:S 1:1000 for 30 min at 37 °C). The signals marked with an asterisk correspond to the mono and doubly charged ions of the intact protein. Peaks at m/z 4361.19 and m/z 10,713.19 were assigned to the complementary peptides 98-132 and 1-97, respectively (marked A and B in the figure) originating from a single proteolytic cleavage between the peptide bond Met97-Lys98. The amino acid sequences of the two peptides (A and B) are shown in the inset and are underlined in red (A) or in green (B) in the upper panel of the figure. The tryptase preferential cleavage site is shown in red.