MASS SPECTROMETRIC CHARACTERIZATION OF TWO NOVEL BIOLOGICALLY ACTIVE PEPTIDES FROM THE VENOM OF SOCIAL WASP Polybia paulista

SOUZA, B. M., MENDES, M. A., MARQUES, M. R., CESAR, L.M.M., SANTOS, L. D., KONNO, K., PALMA, M.S.

CEIS, Department of Biology, IBRC, UNESP, CAT (CEPID/FAPESP), Institute of Immunological Investigation (Millennium Institute/CNPq), Rio Claro, SP.

The venoms of Hymenoptera have been known to cause significant effects such as systemic reactions and allergy. Currently little is known about the structure, chemical composition and mechanisms of action of the toxins present in the venom of wasps from the neotropical regions responsible for the high number of harmful stinging accidents every year. Two novel peptides were isolated and identified from the crude venom of social wasp Polybia paulista. Specifically, using RP-HPLC, thirteen fractions were identified. Two new peptides were identified in the thirteenth fraction, with molecular weights (as determined by ESI-MS) of 1613 Da and 1659 Da.  Further purification of this fraction, allowed sequence determination by ESI-MS/MS spectra to elucidate the following sequences: Ac-S A D I/L P K/Q N D K/Q I/L N G I/L D, 1613Da, and Ac-S P D M V M K/Q G I/L K/Q I/L D I/L G I/L, 1659 Da. The sequence determined by MS/MS was compared with the sequence elucidated from MALDI-TOF-PSD spectra. This comparison indicates the loss of 42 Da from each of the two peptides, confirming acetylation of the N-terminus. Specifically, both peptides contain fourteen amino acid residues each with an acetylated serine at the N-terminus side. The following biological activities were investigated: hemolysis, chemotaxis, mast cell degranulation and antibiotic properties. The results showed that both peptides exhibit potent biological actions, most notably, mast cell degranulation activity.

Supported by FAPESP and CNPq

CORRESPONDENCE TO:

SOUZA, B. M., CEIS, Department of Biology, IBRC, UNESP, CAT (CEPID/FAPESP), Instituteof Immunological Investigation (Millennium Institute/CNPq), Rio Claro, SP, Brasil, Email: bmsouza@hotmail.com