Top-Down Proteomic Identification of Furin-Cleaved α-Subunit of Shiga Toxin 2 from Escherichia coli O157:H7 Using MALDI-TOF-TOF-MS/MS

Figure 4

Bottom-up proteomic sequence coverage of α-Stx2 (in red) from select gel bands (Figure S3, Supplementary Materials). A 22-residue signal peptide (in bold) is removed in the mature protein. Recognition sites for potential furin cleavage (RXXR) are boxed. An asterisk (*) marks the only observed furin cleavage site.