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BmTx3
BmTx3 is a neurotoxin, which is a component of the venom of the scorpion ''Buthus Martensi'' Karsch. It blocks A-type potassium channels in the central nervous system and hERG-channels in the heart. Source/Isolation BmTx3 was originally purified from the venom of the Chinese scorpion, ''Buthus Martensi'' Karsch. BmTx3 is a “short-chain” peptide like other potassium channel blockers in the scorpion venom and added to the phylogenetic tree in the subfamily α-KTx15. Its 3D structure has not yet been elucidated, but based on sequence similarity it likely resembles the 3D structure of BmTx1 or Discrepin. Biochemistry BmTx3 consists of an α-helix and two β-sheet segments cross-linked by three disulfide bridges (Cs-α/β motif). It is a short chain peptide with a molecular mass of 3751.6 Da; it consists of 37 amino acids. Target BmTx3 is the first toxin from the scorpion α-KTx subfamily 15 with two functional faces. As all α-KTx peptides, BmTx3 blocks A-type (IA) potassium ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Discrepin
Discrepin (α-KTx15.6) is a peptide from the venom of the Venezuelan scorpion ''Tityus discrepans''. It acts as a neurotoxin by irreversibly blocking A-type voltage-dependent K+-channels. Etymology and source Discrepin is named after its source: a Venezuelan scorpion called ''Tityus discrepans''. Its systematic number is α-KTx15.6. Chemistry The subfamily α-KTx15 consists of 6 toxins. The first five toxins of this subfamily are very much alike, but discrepin only shares 50% amino acid homology with other members of this subfamily. Discrepin contains 38 amino acid residues. It has a polyglutamic acid at its N-terminal region. Discrepin has the α and β folds that are characteristic of scorpion toxins. It consists of one α-helix and three β-sheet helix strands. The α-helix is formed from amino acid Ser11 until Arg21. The three antiparallel β-sheets are formed from amino acid Ile2 until Lys7, Ala27 until Cys29 and Arg33 until Cys36. Target Discrepin blocks voltage-gated Sh ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |