1OPH

NON-COVALENT COMPLEX BETWEEN ALPHA-1-PI-PITTSBURGH AND S195A TRYPSIN

Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.3 Å
  • R-Value Free: 0.229 
  • R-Value Work: 0.190 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history. 

Literature

Canonical inhibitor-like interactions explain reactivity of alpha1-proteinase inhibitor Pittsburgh and antithrombin with proteinases

Dementiev, A., Simonovic, M., Volz, K., Gettins, P.G.

(2003) J.Biol.Chem. 278: 37881-37887

  • DOI: 10.1074/jbc.M305195200
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 

    • The serpin antithrombin is a slow thrombin inhibitor that requires heparin to enhance its reaction rate. In contrast, alpha1-proteinase inhibitor (alpha1PI) Pittsburgh (P1 Met --> Arg natural variant) inhibits thrombin 17 times faster than pentasacch ...

    The serpin antithrombin is a slow thrombin inhibitor that requires heparin to enhance its reaction rate. In contrast, alpha1-proteinase inhibitor (alpha1PI) Pittsburgh (P1 Met --> Arg natural variant) inhibits thrombin 17 times faster than pentasaccharide heparin-activated antithrombin. We present here x-ray structures of free and S195A trypsin-bound alpha1PI Pittsburgh, which show that the reactive center loop (RCL) possesses a canonical conformation in the free serpin that does not change upon binding to S195A trypsin and that contacts the proteinase only between P2 and P2'. By inference from the structure of heparin cofactor II bound to S195A thrombin, this RCL conformation is also appropriate for binding to thrombin. Reaction rates of trypsin and thrombin with alpha1PI Pittsburgh and antithrombin and their P2 variants show that the low antithrombin-thrombin reaction rate results from the antithrombin RCL sequence at P2 and implies that, in solution, the antithrombin RCL must be in a similar canonical conformation to that found here for alpha1PI Pittsburgh, even in the nonheparin-activated state. This suggests a general, limited, canonical-like interaction between serpins and proteinases in their Michaelis complexes.

    Organizational Affiliation: 

    Department of Biochemistry and Molecular Genetics, College of Medicine, University of Illinois at Chicago, Chicago, Illinois 60607, USA.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Alpha-1-antitrypsin precursor
A
394Homo sapiensMutation(s): 9 
Gene Names: SERPINA1 (AAT, PI)
Find proteins for P01009 (Homo sapiens)
Go to Gene View: SERPINA1
Go to UniProtKB:  P01009
Entity ID: 2
MoleculeChainsSequence LengthOrganismDetails
Trypsinogen, cationic precursor
B
243Bos taurusMutation(s): 1 
EC: 3.4.21.4
Find proteins for P00760 (Bos taurus)
Go to UniProtKB:  P00760
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.3 Å
  • R-Value Free: 0.229 
  • R-Value Work: 0.190 
  • Space Group: C 1 2 1
Unit Cell:
Length (Å)Angle (°)
a = 132.230α = 90.00
b = 62.320β = 110.32
c = 98.880γ = 90.00
Software Package:
Software NamePurpose
DENZOdata reduction
CNSphasing
CNSrefinement
SCALEPACKdata scaling

Structure Validation

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Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2003-08-05
    Type: Initial release
  • Version 1.1: 2008-04-29
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance