CLONING AND DNA SEQUENCING OF A a-PHOSPHOLIPASE A_{2 INHIBITOR ENCODED IN THE LIVER OF Crotalus durissus terrificus}

ESTEVÃO-COSTA, M.I.(1), VELARDE, D.T.(2), MACIEL, R.(2), FORTES-DIAS, C.L.(1)

(1)Centro de Pesquisa e Desenvolvimento e (2)Divisão de Imunobiológicos, Fundação Ezequiel Dias (FUNED), Belo Horizonte, MG.

Several authors have reported the presence of PLA₂ inhibitors in the blood plasma of snake species. These inhibitors have been divided into three classes (alpha, beta and gamma) according to their structure (Ohkura et al., 1997). In the present work we have cloned the cDNA encoding a PLA₂ inhibitor from the a -class in a Brazilian snake species. Total RNA was extracted from the liver of C. d. terrificus (the South American rattlesnake) and submitted to RT-PCR in the presence of specific oligonucleotides, the design of which were based on the published sequence of a similar inhibitor isolated the blood plasma of the Chinese mamushi Agkistrodon blomhoffii siniticus (Ohkura et al., 1997). The amplification product was cloned in TA pCR2.1 vector and putative positive colonies were screened by PCR with appropriate primers. Recombinant clones were subjected to sequencing on an automated DNA sequencer. On the basis of the sequence data generated the complete nucleotide sequence of C. d. terrificus a-PLA₂ inhibitor was determined and compared to members of the a-class of inhibitors from other snake species using the Vector NTI^â software. Structurally, the a-inhibitors display motifs homologous to the carbohydrate recognition domain (CRD) of C-type lectins.

Financial support: FAPEMIG

CORRESPONDENCE TO:

Maria Inacia Estevão Costa, Rua São Clemente 186, Belo Horizonte, MG, CEP: 31230-460, Brasil, Email: miec@uaimail.com.br