1LK6

Structure of dimeric antithrombin complexed with a P14-P9 reactive loop peptide and an exogenous tripeptide


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.80 Å
  • R-Value Free: 0.266 
  • R-Value Work: 0.202 

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This is version 2.0 of the entry. See complete history


Literature

Serpin Polymerization Is Prevented by a Hydrogen Bond Network That Is Centered on His-334 and Stabilized by Glycerol

Zhou, A.Stein, P.E.Huntington, J.A.Carrell, R.W.

(2003) J Biol Chem 278: 15116-15122

  • DOI: 10.1074/jbc.M211663200
  • Primary Citation of Related Structures:  
    1LK6

  • PubMed Abstract: 
  • Polymerization of serpins commonly results from mutations in the shutter region underlying the bifurcation of strands 3 and 5 of the A-sheet, with entry beyond this point being barred by a H-bond network centered on His-334. Exposure of this histidine in antithrombin, which has a partially opened sheet, allows polymerization and peptide insertion to occur at pH 6 or less when His-334 will be predictably protonated with disruption of the H-bond network ...

    Polymerization of serpins commonly results from mutations in the shutter region underlying the bifurcation of strands 3 and 5 of the A-sheet, with entry beyond this point being barred by a H-bond network centered on His-334. Exposure of this histidine in antithrombin, which has a partially opened sheet, allows polymerization and peptide insertion to occur at pH 6 or less when His-334 will be predictably protonated with disruption of the H-bond network. Similarly, thermal stability of antithrombin is pH-dependent with a single unfolding transition at pH 6, but there is no such transition when His-334 is buried by a fully closed A-sheet in heparin-complexed antithrombin or in alpha(1)-antitrypsin. Replacement of His-334 in alpha(1)-antitrypsin by a serine or alanine at pH 7.4 results in the same polymerization and loop-peptide acceptance observed with antithrombin at low pH. The critical role of His-334 and the re-formation of its H-bond network by the conserved P8 threonine, on the full insertion of strand 4, are relevant for the design of therapeutic blocking agents. This is highlighted here by the crystallographic demonstration that glycerol, which at high concentrations blocks polymerization, can replace the P8 threonine and re-form the disrupted H-bond network with His-334.


    Organizational Affiliation

    Department of Haematology, University of Cambridge, Cambridge Institute of Medical Research, Hills Road, Cambridge CB2 2XY, United Kingdom. awz20@cus.cam.ac.uk



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
antithrombin-IIIB [auth I], A [auth L]432Homo sapiensMutation(s): 0 
Gene Names: SERPINC1AT3PRO0309
UniProt & NIH Common Fund Data Resources
Find proteins for P01008 (Homo sapiens)
Explore P01008 
Go to UniProtKB:  P01008
PHAROS:  P01008
Protein Feature View
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  • Reference Sequence
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Entity ID: 2
MoleculeChainsSequence LengthOrganismDetailsImage
antithrombin P14-P9 peptideC7N/AMutation(s): 0 
Protein Feature View
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  • Reference Sequence
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Entity ID: 3
MoleculeChainsSequence LengthOrganismDetailsImage
exogenous tripeptide formyl-MLFD3N/AMutation(s): 0 
Protein Feature View
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  • Reference Sequence
Small Molecules
Modified Residues  1 Unique
IDChainsTypeFormula2D DiagramParent
FME
Query on FME
DL-PEPTIDE LINKINGC6 H11 N O3 SMET
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.80 Å
  • R-Value Free: 0.266 
  • R-Value Work: 0.202 
  • Space Group: P 1 21 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 68.811α = 90
b = 99.908β = 104.44
c = 87.292γ = 90
Software Package:
Software NamePurpose
MOSFLMdata reduction
TRUNCATEdata reduction
CNSrefinement
CCP4data scaling
CNSphasing

Structure Validation

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Ligand Structure Quality Assessment  



Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2003-06-03
    Type: Initial release
  • Version 1.1: 2008-04-02
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Atomic model, Database references, Derived calculations, Non-polymer description, Structure summary, Version format compliance
  • Version 2.0: 2020-07-29
    Type: Remediation
    Reason: Carbohydrate remediation
    Changes: Atomic model, Data collection, Derived calculations, Structure summary