Antibacterial and antifungal properties of α‐helical, cationic peptides in the venom of scorpions from southern Africa

Abstract

Two novel pore-forming peptides have been isolated from the venom of the South-African scorpion Opistophtalmus carinatus. These peptides, designated opistoporin 1 and 2, differ by only one amino acid and belong to a group of a-helical, cationic peptides. For the first time, a comparison of the primary structures of a-helical pore-forming peptides from scorpion venom was undertaken. This analysis revealed that peptides in the range of 40-50 amino acids contain a typical scorpion conserved sequence S(x) 3 KxWxS(x) 5 L. An extensive study of biological activity of synthesized opistoporin 1 and parabutoporin, a poreforming peptide previously isolated from the venom of the South-African scorpion Parabuthus schlechteri, was undertaken to investigate an eventual cell-selective effect of the peptides. Opistoporin 1 and parabutoporin were most active in inhibiting growth of Gram-negative bacteria (1.3-25 lM), while melittin and mastoparan, two well-known cytolytic peptides, were more effective against Gram-positive bacteria in the same concentration range. In addition, the peptides showed synergistic activity with some antibiotics commonly used in therapy. Opistoporin 1 and parabutoporin had hemolytic activity intermediate between the least potent mastoparan and the highly lytic melittin. Furthermore, all peptides inhibited growth of fungi. Experiments with SYTOX green suggested that this effect is related to membrane permeabilization.

Fine structural analysis of the stinger in venom apparatus of the scorpion Euscorpius mingrelicus (Scorpiones: Euscorpiidae)

“…Given its structure and morphology, it may be said that this cell is mobile and probably defensive. Many articles on scorpion venoms, venom chemistry and their medical use are available in the literature (14)(15)(16)(17)(18)(19). However, in order to be able to understand the chemistry and physiology of the venom, one should first know the anatomy, histology and fine structure of the venom gland and the venom stinger.…”

Natural Antimicrobial Peptides from Eukaryotic Organisms

“…In this AMP class arthtropod AMP like Opistoporin-2 from Scorpion Opistophthalmus carinatus are also Natural Antimicrobial Peptides from Eukaryotic Organisms 53 included (Moerman et al, 2002) as well as cathelicidin peptides (Travis et al, 2000) and the fly cecropin from Stomoxys calcitrans (Boulanger et al, 2002). This phylogenetically heterogeneous group present lysine/argine doublet repeats that could be considered as a structural signature.…”

Aislamiento y caracterización de un péptido antibacteriano del veneno de Centruroides margaritatus

“…Actividad antimicótica.-La actividad sobre A. niger, se evaluó en microplacas con pocillos, mezclando 10 µL de una suspensión de 2 x 10 5 esporas/mL en agua destilada, 70 µL de Caldo Saboraud conteniendo 250 ppm de cloranfenicol y 20 µL del péptido antimicrobiano (Moerman et al 2002). Se incubó a temperatura ambiente y el crecimiento se evaluó a las 24, 48, 72 y 120 horas.…”