title: Variability of Potassium Channel Blockers in Mesobuthus eupeus Scorpion Venom with Focus on Kv1.1: AN INTEGRATED TRANSCRIPTOMIC AND PROTEOMIC STUDY.
abstract: The lesser Asian scorpion Mesobuthus eupeus (Buthidae) is one of the most widely spread and dispersed species of the Mesobuthus genus, and its venom is actively studied. Nevertheless, a considerable amount of active compounds is still under-investigated due to the high complexity of this venom. Here, we report a comprehensive analysis of putative potassium channel toxins (KTxs) from the cDNA library of M. eupeus venom glands, and we compare the deduced KTx structures with peptides purified from the venom. For the transcriptome analysis, we used conventional tools as well as a search for structural motifs characteristic of scorpion venom components in the form of regular expressions. We found 59 candidate KTxs distributed in 30 subfamilies and presenting the cysteine-stabilized α/β and inhibitor cystine knot types of fold. M. eupeus venom was then separated to individual components by multistage chromatography. A facile fluorescent system based on the expression of the KcsA-Kv1.1 hybrid channels in Escherichia coli and utilization of a labeled scorpion toxin was elaborated and applied to follow Kv1.1 pore binding activity during venom separation. As a result, eight high affinity Kv1.1 channel blockers were identified, including five novel peptides, which extend the panel of potential pharmacologically important Kv1 ligands. Activity of the new peptides against rat Kv1.1 channel was confirmed (IC50 in the range of 1-780 nm) by the two-electrode voltage clamp technique using a standard Xenopus oocyte system. Our integrated approach is of general utility and efficiency to mine natural venoms for KTxs.
authors: From the Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow 117997, Russia.
authors: Alexey I
authors: AI
authors: Kuzmenkov
authors: From the Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow 117997, Russia, avas@ibch.ru.
authors: Alexander A
authors: AA
authors: Vassilevski
authors: From the Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow 117997, Russia, the Biological Faculty, Lomonosov Moscow State University, Moscow 119992, Russia, and.
authors: Kseniya S
authors: KS
authors: Kudryashova
authors: From the Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow 117997, Russia.
authors: Oksana V
authors: OV
authors: Nekrasova
authors: the Laboratory of Toxicology and Pharmacology, University of Leuven, Leuven 3000, Belgium.
authors: Steve
authors: S
authors: Peigneur
authors: the Laboratory of Toxicology and Pharmacology, University of Leuven, Leuven 3000, Belgium.
authors: Jan
authors: J
authors: Tytgat
authors: From the Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow 117997, Russia, the Biological Faculty, Lomonosov Moscow State University, Moscow 119992, Russia, and.
authors: Alexey V
authors: AV
authors: Feofanov
authors: From the Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow 117997, Russia, the Biological Faculty, Lomonosov Moscow State University, Moscow 119992, Russia, and.
authors: Mikhail P
authors: MP
authors: Kirpichnikov
authors: From the Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow 117997, Russia.
authors: Eugene V
authors: EV
authors: Grishin
mesh_terms: D020816:Amino Acid Motifs; D000595:Amino Acid Sequence; D000818:Animals; D002845:Chromatography; D004926:Escherichia coli / Q000378:metabolism; D005260:Female; D005456:Fluorescent Dyes / Q000737:chemistry; D015723:Gene Library; D020128:Inhibitory Concentration 50; D051662:Kv1.1 Potassium Channel / Q000037:antagonists & inhibitors*; D008024:Ligands; D013058:Mass Spectrometry; D008969:Molecular Sequence Data; D009865:Oocytes; D010802:Phylogeny; D026902:Potassium Channel Blockers / Q000737:chemistry*; D020543:Proteome; D051381:Rats; D012604:Scorpion Venoms / Q000737:chemistry*; D012605:Scorpions; D017386:Sequence Homology, Amino Acid; D014158:Transcription, Genetic; D059467:Transcriptome; D014981:Xenopus
chemical_list: D005456:Fluorescent Dyes; D008024:Ligands; D026902:Potassium Channel Blockers; D020543:Proteome; D012604:Scorpion Venoms; D051662:Kv1.1 Potassium Channel
keywords: Drug Screening; Fluorescence; Molecular Pharmacology; Neurotoxin; Potassium Channel; Protein Chimera; Protein Drug Interaction; Proteomics; Toxin; Transcriptomics