Screening Snake Venoms for Toxicity to Tetrahymena Pyriformis Revealed Anti-Protozoan Activity of Cobra Cytotoxins

• Published in: Toxins Vol. 12; no. 5; p. 325
• Main Authors: Kuleshina, Olga N, Kruykova, Elena V, Cheremnykh, Elena G, Kozlov, Leonid V, Andreeva, Tatyana V, Starkov, Vladislav G, Osipov, Alexey V, Ziganshin, Rustam H, Tsetlin, Victor I, Utkin, Yuri N
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 15.05.2020; MDPI
• Subjects: Animals; Antiprotozoal activity; Antiprotozoal Agents - isolation & purification; Antiprotozoal Agents - pharmacology; Automation; Chromatography; ciliate Tetrahymena pyriformis; cytotoxin; Cytotoxins; Cytotoxins - isolation & purification; Cytotoxins - pharmacology; Elapid Venoms - chemistry; Fluorescence; Fluorescence microscopy; High-performance liquid chromatography; Immobilization; Invertebrates; Ion exchange; Light microscopy; Liquid chromatography; Mass spectrometry; Mass spectroscopy; membrane rupture; Membranes; Microorganisms; Morphology; Optical microscopy; Organisms; Parasitic diseases; Peptides; Peptides - isolation & purification; Peptides - pharmacology; Pollutants; Polypeptides; Proteins; Protozoa; Scientific imaging; snake venom; Snakes; Tetrahymena pyriformis - drug effects; Toxicity; Toxicity testing; Toxins; Tropical diseases; Venom; Venom toxins; Vertebrates; snake venom; cytotoxin; immobilization; ciliate Tetrahymena pyriformis; membrane rupture; protozoa
• ISSN: 2072-6651; 2072-6651
• DOI: 10.3390/toxins12050325

Snake venoms possess lethal activities against different organisms, ranging from bacteria to higher vertebrates. Several venoms were shown to be active against protozoa, however, data about the anti-protozoan activity of cobra and viper venoms are very scarce. We tested the effects of venoms from several snake species on the ciliate . The venoms tested induced immobilization, followed by death, the most pronounced effect being observed for cobra venom. The active polypeptides were isolated from this venom by a combination of gel-filtration, ion exchange and reversed-phase HPLC and analyzed by mass spectrometry. It was found that these were cytotoxins of the three-finger toxin family. The cytotoxins from several cobra species were tested and manifested toxicity for infusorians. Light microscopy revealed that, because of the cytotoxin action, the infusorians' morphology was changed greatly, from teardrop-like to an almost spherical shape, this alteration being accompanied by a leakage of cell contents. Fluorescence microscopy showed that the fluorescently labelled cytotoxin 2 from cobra was localized mainly at the membrane of killed infusorians, indicating that cytotoxins may kill by causing membrane rupture. This work is the first evidence of the antiprotozoal activity of cobra venom cytotoxins, as demonstrated by the example of the ciliate .