2J4F

Torpedo acetylcholinesterase - Hg heavy-atom derivative


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.80 Å
  • R-Value Free: 0.262 
  • R-Value Work: 0.204 
  • R-Value Observed: 0.204 

wwPDB Validation   3D Report Full Report


This is version 1.3 of the entry. See complete history


Literature

A Metastable State of Torpedo Californica Acetylcholinesterase Generated by Modification with Organomercurials

Kreimer, D.I.Dolginova, E.A.Raves, M.Sussman, J.L.Silman, I.Weiner, L.

(1994) Biochemistry 33: 14407

  • DOI: 10.1021/bi00252a006
  • Primary Citation of Related Structures:  
    2J4F

  • PubMed Abstract: 
  • Chemical modification of Torpedo californica acetylcholinesterase by various sulfhydryl reagents results in its conversion to one of two principal states. One of these states, viz., that produced by disulfides and alkylating agents, is stable. The second state, produced by mercury derivatives, is metastable ...

    Chemical modification of Torpedo californica acetylcholinesterase by various sulfhydryl reagents results in its conversion to one of two principal states. One of these states, viz., that produced by disulfides and alkylating agents, is stable. The second state, produced by mercury derivatives, is metastable. At room temperature, it converts spontaneously, with a half-life of ca. 1 h, to a stable state similar to that produced by the disulfides and alkylating agents. Demodification of acetylcholinesterase freshly modified by mercurials, by its exposure to reduced glutathione, causes rapid release of the bound mercurial, with concomitant recovery of most of the enzymic activity of the native enzyme. In contrast, similar demodification of acetylcholinesterase modified by disulfides yields no detectable recovery of enzymic activity. Spectroscopic measurements, employing CD, intrinsic fluorescence, and binding of 1-anilino-8-naphthalenesulfonate, show that the state produced initially by mercurials is "native-like", whereas that produced by disulfides and alkylating agents, and after prolonged incubation of the mercurial-modified enzyme, is partially unfolded and displays many of the features of the "molten globule" state. Arrhenius plots show that the quasi-native state produced by organomercurials is separated by a low (5 kcal/mol) energy barrier from the native state, whereas the partially unfolded state is separated from the quasi-native state by a high energy barrier (ca. 50 kcal/mol). Comparison of the 3D structures of native acetylcholinesterase and of a heavy-atom derivative obtained with HgAc2 suggests that the mercurial-modified enzyme may be stabilized by additional interactions of the mercury atom attached to the free thiol group of Cys231, specifically with Ser228O gamma with the main-chain nitrogen and carbonyl oxygen of the same serine residue.


    Organizational Affiliation

    Department of Neurobiology, Weizmann Institute of Science, Rehovot, Israel.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
ACETYLCHOLINESTERASEA543Tetronarce californicaMutation(s): 0 
Gene Names: ache
EC: 3.1.1.7
UniProt
Find proteins for P04058 (Tetronarce californica)
Explore P04058 
Go to UniProtKB:  P04058
Protein Feature View
Expand
  • Reference Sequence
Small Molecules
Ligands 1 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
HG
Query on HG

Download Ideal Coordinates CCD File 
B [auth A], C [auth A]MERCURY (II) ION
Hg
BQPIGGFYSBELGY-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.80 Å
  • R-Value Free: 0.262 
  • R-Value Work: 0.204 
  • R-Value Observed: 0.204 
  • Space Group: P 31 2 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 110.7α = 90
b = 110.7β = 90
c = 135γ = 120
Software Package:
Software NamePurpose
X-PLORrefinement
XDSdata reduction
XSCALEdata scaling
X-PLORphasing

Structure Validation

View Full Validation Report



Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2006-09-05
    Type: Initial release
  • Version 1.1: 2011-05-08
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Version format compliance
  • Version 1.3: 2021-05-12
    Changes: Derived calculations, Other