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1.C.86 The Pore-forming Trialysin (Trialysin) Family

Triatoma infestans is a hematophagous insect that transmits the protozoan parasite Trypanosoma cruzi, the etiological agent of Chagas disease. Its saliva and salivary glands contain trialysin, a protein that forms pores in membranes. Peptides based on the N-terminus of trialysin lyse cells and fold into alpha-helical amphipathic segments resembling antimicrobial peptides. Trialysin is synthesized as a precursor that is less active than the protein released after saliva secretion. A synthetic peptide flanked by a fluorophore and a quencher including the acidic proregion and the lytic N-terminus of the protein is also less active against cells and liposomes, increasing activity upon proteolysis. Activation changes the peptide conformation as observed by fluorescence increase and CD spectroscopy (Martins et al., 2008). This mechanism of activation might provide a way to impair the toxic effects of trialysin inside the salivary glands.

The transport reaction catalyzed by Trialysin is:

small molecule (in) small molecule (out)

References associated with 1.C.86 family:

Martins, R.M., R. Amino, K.R. Daghastanli, I.M. Cuccovia, M.A. Juliano, and S. Schenkman (2008). A short proregion of trialysin, a pore-forming protein of Triatoma infestans salivary glands, controls activity by folding the N-terminal lytic motif. FEBS J 275: 994-1002. 18221493