DETECTION OF PUTATIVE METALLOPROTEINASES IN ELAPID VENOMS

Checchi, P.(1), Della-Casa, M.S.(1), Kosmiskas, L.O.C.(2), Nascimento, N.(2), Moura da Silva, A.M.(1), Mirtschin, P.(3), Fernandes, I.(1), Spencer, P.J.(1,2)

(1)Laboratório de Imunopatologia, Instituto Butantan, (2)Laboratório de Biologia Molecular, Instituto de Pesquisas Energéticas e Nucleares, São Paulo, Brazil, (3)Venom supplies, Tanunda, Austrália.

Toxins affecting haemostasis are well known to occur in viperid  venoms. In these venoms the major systemic effects can be ascribed to these proteins. Among these toxins, a particularly important group is the snake venom metalloproteinases (SVMP) responsible for the often-massive haemorrhage. Elapid venoms are better known for their neurotoxic action and few haemorhagins have been described in this family.  Our aim was to evaluate the presence of SVMP-related proteins in elapid venoms using antibodies against jararhagin, a P3-SVMP from the pit viper Bothrops jararaca. Equal concentrations (3mg) of Hoplocephalus stephensis, Naja melanoleuca, Naja mossambica, Notechis ater niger, Notechis scutatus, Oxyuranus microlepidotus, Oxyuranus scutellatus, Pseudechis australis, Pseudechis colleti, Pseudechis guttatus, Pseudechis porphyriacus and Pseudonaja textilis venoms were separated by SDS-PAGE and transferred onto a nitrocellulose membrane. The membrane was incubated with mouse polyclonal antibody against jararhagin. The membrane was developed with a rabbit anti-mouse IgG conjugate. In parallel, all the venoms were tested in mice for haemorrhagic activity. Our results indicate that all venoms presented immunoreactive bands. According to their apparent size, a vast majority of the identified proteins appear to belong to the P3 and P4 SVMPs. The only exception we could observe was the N. mossambica venom where a lower molecular weight band was detected, suggesting the presence of a P1 SVMP. Most of the venoms presented haemorrhagic activity when assayed in vivo. According to our observations, different components of the SVMP group are present in the venom of the elapid family,however, in much lower concentration than in viperids. The SVMP genic family appears to be present in both families, with variations of the expression rate. Finally, although mainly neurotoxic, the presence of putatives SVMPs in elapids might be important from the clinical point of view.

CORRESPONDENCE TO:

Spencer, P.J., Laboratório de Imunopatologia, Instituto Butantan, Avenida Vital Brasil, 1500, São Paulo, 05503-900, SP, Brasil, Email: pspencer@net.ipen.br