Kirill A. Pluzhnikov
- (2014). Linear antimicrobial peptides from Ectatomma quadridens ant venom. Biochimie 107 Pt B, 211–5 [+]
Venoms from three poneromorph ant species (Paraponera clavata, Ectatomma quadridens and Ectatomma tuberculatum) were investigated for the growth inhibition of Gram-positive and Gram-negative bacteria. It was shown that the venom of E. quadridens and its peptide fraction in particular possess marked antibacterial action. Three linear antimicrobial peptides sharing low similarity to the well-known ponericin peptides were isolated from this ant venom by means of size-exclusion and reversed-phase chromatography. The peptides showed antimicrobial activity at low micromolar concentrations. Their primary structure was established by direct Edman sequencing in combination with mass spectrometry. The most active peptide designated ponericin-Q42 was chemically synthesized. Its secondary structure was investigated in aqueous and membrane-mimicking environment, and the peptide was shown to be partially helical already in water, which is unusual for short linear peptides. Analysis of its activity on different bacterial strains, human erythrocytes and chronic myelogenous leukemia K562 cells revealed that the peptide shows broad spectrum cytolytic activity at micromolar and submicromolar concentrations. Ponericin-Q42 also possesses weak toxic activity on flesh fly larvae with LD50 of ∼105 μg/g.ID:1150
- (2002). New binding site on common molecular scaffold provides HERG channel specificity of scorpion toxin BeKm-1. J. Biol. Chem. 277 (45), 43104–9 [+]
The scorpion toxin BeKm-1 is unique among a variety of known short scorpion toxins affecting potassium channels in its selective action on ether-a-go-go-related gene (ERG)-type channels. BeKm-1 shares the common molecular scaffold with other short scorpion toxins. The toxin spatial structure resolved by NMR consists of a short alpha-helix and a triple-stranded antiparallel beta-sheet. By toxin mutagenesis study we identified the residues that are important for the binding of BeKm-1 to the human ERG K+ (HERG) channel. The most critical residues (Tyr-11, Lys-18, Arg-20, Lys-23) are located in the alpha-helix and following loop whereas the "traditional" functional site of other short scorpion toxins is formed by residues from the beta-sheet. Thus the unique location of the binding site of BeKm-1 provides its specificity toward the HERG channel.ID:195
- (2001). An ERG channel inhibitor from the scorpion Buthus eupeus. J. Biol. Chem. 276 (13), 9868–76 [+]
The first selective blocker of K+ channels of ERG type BeKm was isolated from the venom of the scorpion Buthus eupeus. The peptide along with its mutants was produced in a heterological expression system and their properties were assessedID:85
on M-currentsin the NG108-15cell line, which allowed establishing the peptide’s pharmacophore. BeKm toxin became the first published selective inhibitor of hERG channels. At present it may be found on the market of bioactive substances.