Isolation of biologically active peptides from the venom of Japanese carpenter bee, .

BACKGROUND

Mass spectrometry-guided venom peptide profiling is a powerful tool to explore novel substances from venomous animals in a highly sensitive manner. In this study, this peptide profiling approach is successfully applied to explore the venom peptides of a Japanese solitary carpenter bee, (Hymenoptera: Apoidea: Apidae: Anthophila: Xylocopinae: Xylocopini). Although interesting biological effects of the crude venom of carpenter bees have been reported, the structure and biological function of the venom peptides have not been elucidated yet.

METHODS

The venom peptide profiling of the crude venom of was performed by matrix-assisted laser desorption/ionization-time of flight mass spectroscopy. The venom was purified by a reverse-phase HPLC. The purified peptides were subjected to the Edman degradation, MS/MS analysis, and/or molecular cloning methods for peptide sequencing. Biological and functional characterization was performed by circular dichroism analysis, liposome leakage assay, and antimicrobial, histamine releasing and hemolytic activity tests.

RESULTS

Three novel peptides with / 16508, 1939.3, and 1900.3 were isolated from the venom of . The peptide with / 16508 was characterized as a secretory phospholipase A (PLA) homolog in which the characteristic cysteine residues as well as the active site residues found in bee PLAs are highly conserved. Two novel peptides with 1939.3 and 1900.3 were named as Xac-1 and Xac-2, respectively. These peptides are found to be amphiphilic and displayed antimicrobial and hemolytic activities. The potency was almost the same as that of mastoparan isolated from the wasp venom.

CONCLUSION

We found three novel biologically active peptides in the venom of and analyzed their molecular functions, and compared their sequential homology to discuss their molecular diversity. Highly sensitive mass analysis plays an important role in this study.