Effects of Arg20 mutation on sodium channels activity of JZTX-V / 生物工程学报
Chinese Journal of Biotechnology
;
(12): 1228-1232, 2008.
Article
in Chinese
| WPRIM
| ID: wpr-275398
ABSTRACT
Jingzhaotoxin-V(JZTX-V) isolated from the venom of the spider Chilobrachys jingzhao is a novel potent inhibitor that acts on tetrodotoxin-resistant and tetrodotoxin-sensitive sodium channels in adult rat dorsal root ganglion(DRG) neurons. It is a 29-residue polypeptide toxin including three disulfide bridges. To investigate the structure-function relationship of the toxin, a mutant of JZTX-V in which Arg20 was substituted by Ala, was synthesized by solid-phase chemistry method with Fmoc-protected amino acids on the PS3 automated peptide synthesizer. The synthetic linear peptide was then purified by reversed-phase high performance liquid chromatography and oxidatively refolded under the optimal conditions. The refolded product was analyzed by matrix-assisted laser desorption/ ionization time-of-flight mass spectrometry(MALDI-TOF MS) and electrophysiological experiments for its relative molecular weight and prohibitive activity of sodium channels respectively. The present findings show that the prohibitive effect of R20A-JZTX-V on TTX-S sodium channels in DRG neurons is almost the same as that of native JZTX-V, suggesting that Arg20 does not play any important role in inhibiting TTX-S sodium currents in DRG neurons. In contrast, the prohibitive level of R20A-JZTX-V on TTX-R sodium channels is reduced by at last 18.3 times, indicating that Arg20 is a key amino acid residue relative to the bioactivity of JZTX-V. It is presumed that the decrease in activity of R20A-JZTX-V is due to the changes of the property in the binding site in TTX-R sodium channels.
Full text:
Available
Index:
WPRIM (Western Pacific)
Main subject:
Peptides
/
Pharmacology
/
Arginine
/
Spider Venoms
/
Spiders
/
Tetrodotoxin
/
Sodium Channels
/
Chemistry
/
Mutagenesis, Site-Directed
/
Patch-Clamp Techniques
Limits:
Animals
Language:
Chinese
Journal:
Chinese Journal of Biotechnology
Year:
2008
Type:
Article
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