1rji
From Proteopedia
Solution Structure of BmKX, a novel potassium channel blocker from the Chinese Scorpion Buthus martensi Karsch
Structural highlights
FunctionSCKI_MESMA Does not show any effect on Na(+), Ca(2+) currents, nor on voltage-gated and calcium-activated potassium channels. Publication Abstract from PubMedScorpion venom is a rich source of bioactive peptides. From the venom of Chinese scorpion Buthus martensi Karsch (BmK), a novel short chain peptide BmKX of 31-amino acid residues was purified, and its amino acid sequence and gene structure were determined. The gene of BmKX was composed of two exons interrupted by an 86-bp intron at the codon-7 upstream of the mature peptide. Although its gene structure is similar to those of other known scorpion toxins, its amino acid sequence, especially the cysteine framework, is different from those of all other known subfamilies of short-chain scorpion toxins. The solution structure of BmKX, determined with two-dimensional NMR spectroscopy, shows that BmKX also forms a typical cysteine-stabilized alpha/beta scaffold adopted by most short-chain scorpion toxins, consisting of a short 3(10)-helix and a two-stranded antiparallel beta-sheet, and the short N-terminal segment forms a pseudo-strand of the beta-sheet. However, the orientation between the helix and the beta-sheet is significantly different from the others, which might be the reason for its unique but still unclear physiological function. A novel short-chain peptide BmKX from the Chinese scorpion Buthus martensi Karsch, sequencing, gene cloning and structure determination.,Wang CG, Cai Z, Lu W, Wu J, Xu Y, Shi Y, Chi CW Toxicon. 2005 Mar 1;45(3):309-19. Epub 2005 Jan 20. PMID:15683869[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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Categories: Large Structures | Mesobuthus martensii | Cai Z | Chi C-W | Shi Y | Wang C-G | Wu J | Xu Y