5K6D

Structure of FS50 an antagonist of NaV1.5


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.139 Å
  • R-Value Free: 0.174 
  • R-Value Work: 0.167 

wwPDB Validation 3D Report Full Report


This is version 1.0 of the entry. See complete history

Literature

Structure and Function of FS50, a salivary protein from the flea Xenopsylla cheopis that blocks the sodium channel NaV1.5.

Xu, X.Zhang, B.Yang, S.An, S.Ribeiro, J.M.Andersen, J.F.

(2016) Sci Rep 6: 36574-36574

  • DOI: 10.1038/srep36574

  • PubMed Abstract: 
  • Naturally occurring toxins have been invaluable tools for the study of structural and functional relationships of voltage-gated sodium channels (VGSC). Few studies have been made of potential channel-modulating substances from blood-feeding arthropod ...

    Naturally occurring toxins have been invaluable tools for the study of structural and functional relationships of voltage-gated sodium channels (VGSC). Few studies have been made of potential channel-modulating substances from blood-feeding arthropods. He we describe the characterization FS50, a salivary protein from the flea, Xenopsylla cheopis, that exhibits an inhibitory activity against the NaV1.5 channel with an IC50 of 1.58 μM. The pore-blocking mechanism of this toxin is evident from the kinetics of activation and inactivation suggesting that FS50 does not interfere with the voltage sensor of NaV1.5. FS50 exhibits high specificity for NaV1.5, since 10 μM FS50 had no discernable effect on voltage-gated Na+, K+ and Ca2+ channels in rat dorsal root ganglia or VGSC forms individually expressed in HEK 293T cells. Furthermore, intravenous injection of FS50 into rats and monkeys elicited recovery from arrhythmia induced by BaCl2, as would be expected from a blockade of NaV1.5. The crystal structure of FS50 revealed a βαββ domain similar to that of scorpion β toxin and a small N-terminal βαβ domain. Site-directed mutagenesis experiments have implicated a basic surface including the side chains of Arg 6, His 11 and Lys 32 as potentially important in the FS50 NaV1.5 interaction.


    Organizational Affiliation

    Guangdong Provincial Key Laboratory of New Drug Screening, School of Pharmaceutical Sciences, Southern Medical University, Guangzhou 510515, Guangdong, China.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Putative secreted salivary protein
A, B
78Xenopsylla cheopisMutation(s): 0 
Find proteins for A2IAD2 (Xenopsylla cheopis)
Go to UniProtKB:  A2IAD2
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.139 Å
  • R-Value Free: 0.174 
  • R-Value Work: 0.167 
  • Space Group: C 1 2 1
Unit Cell:
Length (Å)Angle (°)
a = 60.251α = 90.00
b = 66.627β = 121.69
c = 42.285γ = 90.00
Software Package:
Software NamePurpose
HKL-2000data collection
PHENIXrefinement
HKL-2000data scaling
PDB_EXTRACTdata extraction
HKL-2000data reduction
SHELXphasing

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

  • Deposited Date: 2016-05-24 
  • Released Date: 2016-11-23 
  • Deposition Author(s): Andersen, J.F., Xu, X.

Revision History 

  • Version 1.0: 2016-11-23
    Type: Initial release