1XZ3

Complex of apoferritin with isoflurane


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.75 Å
  • R-Value Free: 0.210 
  • R-Value Work: 0.179 

wwPDB Validation 3D Report Full Report


This is version 1.3 of the entry. See complete history

Literature

Structural basis for high-affinity volatile anesthetic binding in a natural 4-helix bundle protein.

Liu, R.Loll, P.J.Eckenhoff, R.G.

(2005) Faseb J. 19: 567-576

  • DOI: 10.1096/fj.04-3171com
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 
  • Physiologic sites for inhaled anesthetics are presumed to be cavities within transmembrane 4-alpha-helix bundles of neurotransmitter receptors, but confirmation of binding and structural detail of such sites remains elusive. To provide such detail, w ...

    Physiologic sites for inhaled anesthetics are presumed to be cavities within transmembrane 4-alpha-helix bundles of neurotransmitter receptors, but confirmation of binding and structural detail of such sites remains elusive. To provide such detail, we screened soluble proteins containing this structural motif, and found only one that exhibited evidence of strong anesthetic binding. Ferritin is a 24-mer of 4-alpha-helix bundles; both halothane and isoflurane bind with K(A) values of approximately 10(5) M(-1), higher than any previously reported inhaled anesthetic-protein interaction. The crystal structures of the halothane/apoferritin and isoflurane/apoferritin complexes were determined at 1.75 A resolution, revealing a common anesthetic binding pocket within an interhelical dimerization interface. The high affinity is explained by several weak polar contacts and an optimal host/guest packing relationship. Neither the acidic protons nor ether oxygen of the anesthetics contribute to the binding interaction. Compared with unliganded apoferritin, the anesthetic produced no detectable alteration of structure or B factors. The remarkably high affinity of the anesthetic/apoferritin complex implies greater selectivity of protein sites than previously thought, and suggests that direct protein actions may underlie effects at lower than surgical levels of anesthetic, including loss of awareness.


    Organizational Affiliation

    Department of Anesthesia, University of Pennsylvania, Philadelphia, Pennsylvania, USA.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Ferritin light chain
A
174Equus caballusMutation(s): 0 
Gene Names: FTL
Find proteins for P02791 (Equus caballus)
Go to Gene View: FTL
Go to UniProtKB:  P02791
Small Molecules
Ligands 2 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
ICF
Query on ICF

Download SDF File 
Download CCD File 
A
1-CHLORO-2,2,2-TRIFLUOROETHYL DIFLUOROMETHYL ETHER
ISOFLURANE
C3 H2 Cl F5 O
PIWKPBJCKXDKJR-PVQJCKRUSA-N
 Ligand Interaction
CD
Query on CD

Download SDF File 
Download CCD File 
A
CADMIUM ION
Cd
WLZRMCYVCSSEQC-UHFFFAOYSA-N
 Ligand Interaction
External Ligand Annotations 
IDBinding Affinity (Sequence Identity %)
ICFKa: ~100000 M-1 BINDINGMOAD
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.75 Å
  • R-Value Free: 0.210 
  • R-Value Work: 0.179 
  • Space Group: F 4 3 2
Unit Cell:
Length (Å)Angle (°)
a = 181.510α = 90.00
b = 181.510β = 90.00
c = 181.510γ = 90.00
Software Package:
Software NamePurpose
REFMACrefinement
d*TREKdata scaling
MAR345data collection

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2005-05-10
    Type: Initial release
  • Version 1.1: 2008-04-30
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Advisory, Derived calculations, Version format compliance
  • Version 1.3: 2017-10-11
    Type: Refinement description