Received: May 15, 2009.

Accepted: July 1, 2009.

Abstract published online: July 7, 2009.

Full paper published online: November 30, 2009

IDENTIFICATION OF BRADYKININ-RELATED PEPTIDES FROM Phyllomedusa nordestina SKIN SECRETION USING ELECTROSPRAY IONIZATION TANDEM MASS SPECTROMETRY AFTER A SINGLE-STEP LIQUID CHROMATOGRAPHY

Conceição K (1), Bruni FM (1), Sciani JM (3), Konno K (1), Melo RL (1), Antoniazzi MM (2), Jared C (2), Lopes-Ferreira M (1), Pimenta DC (3)

(1) Special Laboratory of Applied Toxinology, Center for Applied Toxinology, CAT/CEPID, Butantan Institute, São Paulo, São Paulo State, Brazil; (2) Laboratory of Cell Biology, Center for Applied Toxinology, CAT/CEPID, Butantan Institute, São Paulo, São Paulo State, Brazil; (3) Laboratory of Biochemistry and Biophysics, Butantan Institute, São Paulo, São Paulo State, Brazil.

ABSTRACT: Amphibian skin secretions are a source of potential new drugs with medical and biotechnological applications. Rich in peptides produced by holocrine-type serous glands in the integument, these secretions play different roles, either in the regulation of physiological skin functions or in the defense against predators or microorganisms. The aim of the present work was to identify novel peptides with bradykinin-like structure and/or activity present in the skin of Phyllomedusa nordestina. In order to achieve this goal, the crude skin secretion of this frog was pre-fractionated by solid phase extraction and separated by reversed-phase chromatography. The fractions were screened for low-molecular-mass peptides and sequenced by mass spectrometry. It was possible to identify three novel bradykinin-related peptides, namely: KPLWRL-NH2 (Pnor 3), RPLSWLPK (Pnor 5) and VPPKGVSM (Pnor 7) presenting vascular activities as assessed by intravital microscopy. Pnor 3 and Pnor 7 were able to induce vasodilation. On the other hand, Pnor 5 was a potent vasoconstrictor. These effects were reproduced by their synthetic analogues.

KEY WORDS: Phyllomedusa nordestina, bradykinin, mass spectrometry, natural peptides.

CONFLICTS OF INTEREST: There is no conflict.

FINANCIAL SOURCE: FAPESP, CAPES and CNPq.

CORRESPONDENCE TO:

DANIEL CARVALHO PIMENTA, Avenida Vital Brazil, 1500, São Paulo, SP, 05503-900, Brasil. Phone/fax: + 55 11 3726 72 22, ext. 2101. Email: dcpimenta@butantan.gov.br.