CLONING OF ANTIMICROBIAL-OPIOID PEPTIDES FROM THE SKIN OF Prhynohyas venulosa (HYLIDAE)

Conceição, K.(1), Rádis-Baptista, G.(1), K.; Kubo, T.(2), Antoniazzi, M. M.(3), Jared, C.(3), Yamane, T.(1)

(1)Molecular Toxinology Lab, Butantan Institute, São Paulo, (2)Molecular Neurobiology Lab, AIST, Tsukuba, (3)Dept. of Cellular Biology, Butantan Institute, São Paulo, Brazil.

The innate immunity is the key component of the host first defense mechanism against pathogens in organisms as diverse as plants, insects, lower vertebrates, and mammalian. More than six hundred structures with antimicrobial activity against encapsulated virus, bacteria and fungi have been compiled. In general, a family of peptides belonging to one determined class is detected in different biological source. This results from the hypermutation of mature peptide and an extremely conserved signal peptide – an indication that a high selective pressure operates to preserve an efficient “cassette of secretion”. To identify precursors of bioactive peptides in the frog skin of Phrynohyas venulosa – a Hylidae that inhabits the Brazilian “Cerrado”, a cDNA library was constructed. Based on conserved signal peptide sequence, oligonucleotides were synthesized and used to screen the recombinant bacteriophage clones. By this approach, we identified, so far, three new antimocrobial-opiod pre-propeptide precursors that share some sequence similarity with dermaseptin-dermorphin members, isolated by several research groups, from the skin of Phyllomedusa specimens. The biochemical and molecular evolutionary aspects of these peptides are presented and discussed.

Support: FAPESP

CORRESPONDENCE TO:

GANDHI RÁDIS BAPTISTA, Avenida Miruna, 1808, São Paulo, SP, CEP: 04084-006, Brasil, Email: radisbra@yahoo.com