Table 1: Measured molecular masses and deduced amino acid sequences obtained by ESI-MS/MS based on the alkylated tryptic peptides of BrTX-I. The peptides were separated by RP-HPLC and sequenced by mass spectrometry. C = alkylated cysteine, lysine residues shown in bold were deduced on the cleavage and missed cleavage by trypsin. All molecular masses are reported as monoisotopic.

BrTX-I HPLC fractionMeasured mass (Da)Amino acid sequenceTheoretical mass (Da)

11360.65DL/IWQ/KWNK/QMI/LK/Q1360.61
21404.67DI/LTI/LVCGEDL/IPCK/Q1404.64
31791.07AAAVCFYENL/IGTYNK/QK/Q1791.03
41120.28YGCYCGWGGR1020.25
5616.79L/ITGCPK/Q616.75