Due to the external calibration applied to all the spectra, it was also not possible to distinguish between Gln and Lys residues based on the 0.035???Da that separates these amino acids, except for Lys, marked in bold in Table 1, which was deduced by analysis of the cleavage and missed cleavage sites of the enzyme.Each de novo sequenced peptide of the BrTX-I was submitted separately to the NCBI da