1jlz
From Proteopedia
(New page: 200px<br /><applet load="1jlz" size="450" color="white" frame="true" align="right" spinBox="true" caption="1jlz" /> '''Solution Structure of a K+-Channel Blocker f...) |
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'''Solution Structure of a K+-Channel Blocker from the Scorpion Toxin of Tityus cambridgei'''<br /> | '''Solution Structure of a K+-Channel Blocker from the Scorpion Toxin of Tityus cambridgei'''<br /> | ||
==Overview== | ==Overview== | ||
| - | A new K(+)-channel blocking peptide identified from the scorpion venom of | + | A new K(+)-channel blocking peptide identified from the scorpion venom of Tityus cambridgei (Tc1) is composed of 23 amino acid residues linked with three disulfide bridges. Tc1 is the shortest known toxin from scorpion venom that recognizes the Shaker B K(+) channels and the voltage-dependent K(+) channels in the brain. Synthetic Tc1 was produced using solid-phase synthesis, and its activity was found to be the same as that of native Tc1. The pairings of three disulfide bridges in the synthetic Tc1 were identified by NMR experiments. The NMR solution structures of Tc1 were determined by simulated annealing and energy-minimization calculations using the X-PLOR program. The results showed that Tc1 contains an alpha-helix and a 3(10)-helix at N-terminal Gly(4)-Lys(10) and a double-stranded beta-sheet at Gly(13)-Ile(16) and Arg(19)-Tyr(23), with a type I' beta-turn at Asn(17)-Gly(18). Superposition of each structure with the best structure yielded an average root mean square deviation of 0.26 +/- 0.05 A for the backbone atoms and of 1.40 +/- 0.23 A for heavy atoms in residues 2 to 23. The three-dimensional structure of Tc1 was compared with two structurally and functionally related scorpion toxins, charybdotoxin (ChTx) and noxiustoxin (NTx). We concluded that the C-terminal structure is the most important region for the blocking activity of voltage-gated (Kv-type) channels for scorpion K(+)-channel blockers. We also found that some of the residues in the larger scorpion K(+)-channel blockers (31 to 40 amino acids) are not involved in K(+)-channel blocking activity. |
==About this Structure== | ==About this Structure== | ||
| - | 1JLZ is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/ ]. Full crystallographic information is available from [http:// | + | 1JLZ is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/ ]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1JLZ OCA]. |
==Reference== | ==Reference== | ||
Solution structure of a K(+)-channel blocker from the scorpion Tityus cambridgei., Wang I, Wu SH, Chang HK, Shieh RC, Yu HM, Chen C, Protein Sci. 2002 Feb;11(2):390-400. PMID:[http://ispc.weizmann.ac.il//pmbin/getpm?pmid=11790849 11790849] | Solution structure of a K(+)-channel blocker from the scorpion Tityus cambridgei., Wang I, Wu SH, Chang HK, Shieh RC, Yu HM, Chen C, Protein Sci. 2002 Feb;11(2):390-400. PMID:[http://ispc.weizmann.ac.il//pmbin/getpm?pmid=11790849 11790849] | ||
[[Category: Single protein]] | [[Category: Single protein]] | ||
| - | [[Category: Chang, H | + | [[Category: Chang, H K.]] |
[[Category: Chen, C.]] | [[Category: Chen, C.]] | ||
| - | [[Category: Shieh, R | + | [[Category: Shieh, R C.]] |
[[Category: Wang, I.]] | [[Category: Wang, I.]] | ||
| - | [[Category: Wu, S | + | [[Category: Wu, S H.]] |
| - | [[Category: Yu, H | + | [[Category: Yu, H M.]] |
[[Category: alpha-ktx]] | [[Category: alpha-ktx]] | ||
[[Category: k+-channel blocker]] | [[Category: k+-channel blocker]] | ||
| Line 23: | Line 23: | ||
[[Category: scorpion venom]] | [[Category: scorpion venom]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 13:24:08 2008'' |
Revision as of 11:24, 21 February 2008
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Solution Structure of a K+-Channel Blocker from the Scorpion Toxin of Tityus cambridgei
Overview
A new K(+)-channel blocking peptide identified from the scorpion venom of Tityus cambridgei (Tc1) is composed of 23 amino acid residues linked with three disulfide bridges. Tc1 is the shortest known toxin from scorpion venom that recognizes the Shaker B K(+) channels and the voltage-dependent K(+) channels in the brain. Synthetic Tc1 was produced using solid-phase synthesis, and its activity was found to be the same as that of native Tc1. The pairings of three disulfide bridges in the synthetic Tc1 were identified by NMR experiments. The NMR solution structures of Tc1 were determined by simulated annealing and energy-minimization calculations using the X-PLOR program. The results showed that Tc1 contains an alpha-helix and a 3(10)-helix at N-terminal Gly(4)-Lys(10) and a double-stranded beta-sheet at Gly(13)-Ile(16) and Arg(19)-Tyr(23), with a type I' beta-turn at Asn(17)-Gly(18). Superposition of each structure with the best structure yielded an average root mean square deviation of 0.26 +/- 0.05 A for the backbone atoms and of 1.40 +/- 0.23 A for heavy atoms in residues 2 to 23. The three-dimensional structure of Tc1 was compared with two structurally and functionally related scorpion toxins, charybdotoxin (ChTx) and noxiustoxin (NTx). We concluded that the C-terminal structure is the most important region for the blocking activity of voltage-gated (Kv-type) channels for scorpion K(+)-channel blockers. We also found that some of the residues in the larger scorpion K(+)-channel blockers (31 to 40 amino acids) are not involved in K(+)-channel blocking activity.
About this Structure
1JLZ is a Single protein structure of sequence from [1]. Full crystallographic information is available from OCA.
Reference
Solution structure of a K(+)-channel blocker from the scorpion Tityus cambridgei., Wang I, Wu SH, Chang HK, Shieh RC, Yu HM, Chen C, Protein Sci. 2002 Feb;11(2):390-400. PMID:11790849
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