Characterization of honeybee venom by MALDI-TOF and nanoESI-QqTOF mass spectrometry.

The aim of the study was to comprehensively characterize different honeybee venom samples applying two complementary mass spectrometry methods. 41 honeybee venom samples of different bee strains, country of origin (Poland, Georgia, and Estonia), year and season of the venom collection were analyzed using MALDI-TOF and nanoESI-QqTOF-MS. It was possible to obtain semi-quantitative data for 12 different components in selected honeybee venom samples using MALDI-TOF method without further sophisticated and time consuming sample pretreatment. Statistical analysis (ANOVA) has shown that there are qualitative and quantitative differences in the composition between honeybee venom samples collected over different years. It has also been demonstrated that MALDI-TOF spectra can be used as a "protein fingerprint" of honeybee venom in order to confirm the identity of the product. NanoESI-QqTOF-MS was applied especially for identification purposes. Using this technique 16 peptide sequences were identified, including melittin (12 different breakdown products and precursors), apamine, mast cell degranulating peptide and secapin. Moreover, the significant achievement of this study is the fact that the new peptide (HTGAVLAGV+Amidated (C-term), M(r)=822.53Da) has been discovered in bee venom for the first time.