LyeTx I, a potent antimicrobial peptide from the venom of the spider Lycosa erythrognatha

Abstract

LyeTx I, an antimicrobial peptide isolated from the venom of Lycosa erythrognatha, known as wolf spider, has been synthesised and its structural profile studied by using the CD and NMR techniques. LyeTx I has shown to be active against bacteria (Escherichia coli and Staphylococcus aureus) and fungi (Candida krusei and Cryptococcus neoformans) and able to alter the permeabilisation of L: -alpha-phosphatidylcholine-liposomes (POPC) in a dose-dependent manner. In POPC containing cholesterol or ergosterol, permeabilisation has either decreased about five times or remained unchanged, respectively. These results, along with the observed low haemolytic activity, indicated that antimicrobial membranes, rather than vertebrate membranes seem to be the preferential targets. However, the complexity of biological membranes compared to liposomes must be taken in account. Besides, other membrane components, such as proteins and even specific lipids, cannot be discarded to be important to the preferential action of the LyeTx I to the tested microorganisms. The secondary structure of LyeTx I shows a small random-coil region at the N-terminus followed by an alpha-helix that reached the amidated C-terminus, which might favour the peptide-membrane interaction. The high activity against bacteria together with the moderate activity against fungi and the low haemolytic activity have indicated LyeTx I as a good prototype for developing new antibiotic peptides.

Peptides as toxins/defensins

“…This issue is intended to present snapshots of the peptides identified as toxins/ defensins and to explore the diversity of biological systems, novel structures, and the mechanisms of action. The reviews and original manuscripts in this issue focus on peptides from insects Leite et al 2010), spiders Rodríguez et al 2010;Santos et al 2010), amphibians Libério et al 2010;Meneses et al 2010), and humans (Corrales-Garcia et al 2010) by using spectroscopic strategies for the detection, structural elucidation De Souza et al 2010;Leite et al 2010), and characterization of the molecular interactions with biological membranes Zhou et al 2010). Some of the contributions focus on the studies of the structure-activity relationship to achieve a better understanding of the mechanisms of the action .…”

“…Some of the contributions focus on the studies of the structure-activity relationship to achieve a better understanding of the mechanisms of the action . A series of novel and classical biological assays is reported to screen peptides for antimicrobial (KuhnNentwig et al 2010;Rodríguez et al 2010;Santos et al …”

Latarcins: versatile spider venom peptides

“…Some LP are bradykinin-potentiating, some possess potent insecticidal activity, and many others are cytotoxic to mammalian cells, fungi, bacteria, trypanosomes, plasmodia, or human cancer cells [6,20,28,39,[44][45][46][47][48][49]. This is probably because LP are rather flexible and can interact with a plethora of biological molecules, ranging from lipids and carbohydrates to proteins and nucleic acids (Fig.…”

Insights into Antimicrobial Peptides from Spiders and Scorpions

“…The known 3D structures of AMPs can be classified into four families: α-helices, β-sheets, mixed αβ structures, and non-αβ structures (no α or β structure) [52]. Of the seven known spider structures, five are α-helical (Figure 1, A–D) [16,53–55] and two are β-sheet peptides (Figure 1, E and F) [56,57]. The NMR structure of spider lyeTx I [55] was not found in the PDB.…”