1hp2: Difference between revisions
No edit summary |
No edit summary |
||
| Line 1: | Line 1: | ||
[[Image:1hp2.jpg|left|200px]] | [[Image:1hp2.jpg|left|200px]] | ||
'''SOLUTION STRUCTURE OF A TOXIN FROM THE SCORPION TITYUS SERRULATUS (TSTX-K ALPHA) DETERMINED BY NMR.''' | {{Structure | ||
|PDB= 1hp2 |SIZE=350|CAPTION= <scene name='initialview01'>1hp2</scene> | |||
|SITE= | |||
|LIGAND= | |||
|ACTIVITY= | |||
|GENE= | |||
}} | |||
'''SOLUTION STRUCTURE OF A TOXIN FROM THE SCORPION TITYUS SERRULATUS (TSTX-K ALPHA) DETERMINED BY NMR.''' | |||
==Overview== | ==Overview== | ||
| Line 7: | Line 16: | ||
==About this Structure== | ==About this Structure== | ||
1HP2 is a [ | 1HP2 is a [[Single protein]] structure of sequence from [http://en.wikipedia.org/wiki/Tityus_serrulatus Tityus serrulatus]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1HP2 OCA]. | ||
==Reference== | ==Reference== | ||
Interaction of a toxin from the scorpion Tityus serrulatus with a cloned K+ channel from squid (sqKv1A)., Ellis KC, Tenenholz TC, Jerng H, Hayhurst M, Dudlak CS, Gilly WF, Blaustein MP, Weber DJ, Biochemistry. 2001 May 22;40(20):5942-53. PMID:[http:// | Interaction of a toxin from the scorpion Tityus serrulatus with a cloned K+ channel from squid (sqKv1A)., Ellis KC, Tenenholz TC, Jerng H, Hayhurst M, Dudlak CS, Gilly WF, Blaustein MP, Weber DJ, Biochemistry. 2001 May 22;40(20):5942-53. PMID:[http://www.ncbi.nlm.nih.gov/pubmed/11352729 11352729] | ||
[[Category: Single protein]] | [[Category: Single protein]] | ||
[[Category: Tityus serrulatus]] | [[Category: Tityus serrulatus]] | ||
| Line 22: | Line 31: | ||
[[Category: scorpion toxin]] | [[Category: scorpion toxin]] | ||
''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Mar 20 11:39:56 2008'' | ||
Revision as of 12:39, 20 March 2008
| |||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||
SOLUTION STRUCTURE OF A TOXIN FROM THE SCORPION TITYUS SERRULATUS (TSTX-K ALPHA) DETERMINED BY NMR.
OverviewOverview
A toxin from the scorpion Tityus serrulatus (TsTX-Kalpha) blocks native squid K(+) channels and their cloned counterpart, sqKv1A, at pH 8 ((native)K(d) approximately 20 nM; (sqKv1A)K(d) approximately 10 nM). In both cases, decreasing the pH below 7.0 significantly diminishes the TsTX-Kalpha effect (pK = 6.6). In the cloned squid channel, the pH dependence of the block is abolished by a single point mutation (H351G), and no change in toxin affinity was observed at higher pH values (pH > or =8.0). To further investigate the TsTX-Kalpha-sqKv1A interaction, the three-dimensional structure of TsTX-Kalpha was determined in solution by NMR spectroscopy, and a model of the TsTX-Kalpha-sqKv1A complex was generated. As found for other alpha-K toxins such as charybdotoxin (CTX), site-directed mutagenesis at toxin residue K27 (K27A, K27R, and K27E) significantly reduced the toxin's affinity for sqKv1A channels. This is consistent with the TsTX-Kalpha-sqKv1A model reported here, which has K27 of the toxin inserted into the ion conduction pathway of the K(+) channel. This toxin-channel model also illustrates a possible mechanism for the pH-dependent block whereby lysine residues from TsTX-Kalpha (K6 and K23) are repelled by protonated H351 on sqKv1A at low pH.
About this StructureAbout this Structure
1HP2 is a Single protein structure of sequence from Tityus serrulatus. Full crystallographic information is available from OCA.
ReferenceReference
Interaction of a toxin from the scorpion Tityus serrulatus with a cloned K+ channel from squid (sqKv1A)., Ellis KC, Tenenholz TC, Jerng H, Hayhurst M, Dudlak CS, Gilly WF, Blaustein MP, Weber DJ, Biochemistry. 2001 May 22;40(20):5942-53. PMID:11352729
Page seeded by OCA on Thu Mar 20 11:39:56 2008