CMx trypsin inhibitors expressed in Butte 86. Differential signal peptide cleavage sites for the CMx inhibitors are indicated with the arrow and zig-zag line. Peptides obtained by MS/MS that distinguish individual CMx proteins are enclosed in shaded boxes. Total MS/MS coverage of CMx Bu-1 in protein spot 280 from Dupont et al.  was 36%, CMx Bu-2 in spot 290 was 57% and CMx Bu-3 in spot 281 was 60% (Additional file 5).