Biochemical Characterization Of Peptides Present In The Skin Of Prhynohyas venulosa (Hylidae).

Conceição, K.¹; Pimenta, D. C.²; Antoniazzi, M. M.³; Jared, C.³; Sant’Anna, O. A.⁴ & Yamane, T.¹

1 Molecular Toxinology Lab. 2 Center for Applied Toxinology, 3 Dept. of Cellular Biology. 4 Microbiology Special Lab. - Butantan Institute, São Paulo – SP - Brazil

Amphibian skin is a rich source of biologically active compounds, such as biogenic amines, complex alkaloids and peptides, which are produced by holocrine-type serous glands in the integument, where they are stored and released upon stimulation. These compounds play roles either in the regulation of physiological functions of the skin or in the defense against predators or microorganisms. Aiming to identify novel bioactive peptides present in Phrynohyasvenulosa  skin – a Hylidae that inhabits the Brazilian “Cerrado”, skin secretion was obtained by manual compression and collected in distilled water, lyophilized and fractioned by reverse phase HPLC, yielding 16 fractions manually separated according to the peak shape in the chromatogram. These fractions were analyzed by MALDI-ToF mass spectrometry and a molecular weight profile of the peptides secreted to the amphibian skin was determined. It was possible to identify, directly from the crude extract, 40 peptides within the range of 1000 to 2000 Da,  10 peptides between 2000 and 3000 Da and 10 peptides heavier than 3000 Da. These molecular weights are representative of the known bioactive peptides already isolated from frogs. Current work is in progress, involving the re-chromatography of the fractions, new MALDI-ToF analysis and ‘de novo’ sequencing of the peptides. These results show that Prhynohyasvenulosa skin secretion is a fruitful source of peptides that are very likely to present biological activities similar to the other members of the family.

Supported by FAPESP and CAT/CEPID

Correspondence to: conceicaokatia@butantan.gov.br