Specificity And Structural Analysis Of Convulxin.

¹Murakami, M.T.; ¹Zela, S.P.; ¹Arni, R.K. 

1 Departamento de Física IBILCE/UNESP – São José do Rio Preto, São Paulo.

A number of the hemostatically active proteins, belonging to the C-type lectin family, have been isolated from the venom of snake species. Several heterodimeric C-type lectins affect the interaction between von Willebrand factor (vWF) and platelet glycoproteins (GP). Convulxin (CVX), a multi-heterodimeric C-type lectin isolated from the venom of  Crotalusdurrisus terrificus, is a potent platelet agonist which functions via a Ca²⁺ dependent mechanism. CVX activates mammalian platelets through a mechanism that involves binding and clustering of GPVI receptors. GPVI is a platelet receptor for collagen which displays a major role in activation  of the agreggation of the platelets. Majoritory GP binding proteins exhibit dual specificity for GPIba and GPVI, as alboaggregin A and alboxin. However, CVX acts mainly via GPVI-binding, as ophioluxin and stejnulxin. Thus, CVX serves as important tool to understand the GPVI-regulated signalling. CVX is the first multimeric C-type lectin that acts specifically via GPVI whose crystal structure has been determined (Murakami et al., 2003 a,b).The structural characterization of CVX and the results of molecular modeling of the interactions between CVX and GP binding proteins will be presented.

Support: FAPESP and CNPq.

Correspondence to: qualitus@uol.com.br