6BVH

Trypsin complexed with a modified sunflower trypsin inhibitor, SFTI-TCTR(N12,N14)


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.93 Å
  • R-Value Free: 0.158 
  • R-Value Work: 0.132 
  • R-Value Observed: 0.133 

wwPDB Validation   3D Report Full Report


This is version 1.1 of the entry. See complete history


Literature

Potent, multi-target serine protease inhibition achieved by a simplified beta-sheet motif.

Chen, X.Riley, B.T.de Veer, S.J.Hoke, D.E.Van Haeften, J.Leahy, D.Swedberg, J.E.Brattsand, M.Hartfield, P.J.Buckle, A.M.Harris, J.M.

(2019) PLoS One 14: e0210842-e0210842

  • DOI: 10.1371/journal.pone.0210842
  • Primary Citation of Related Structures:  
    6BVH

  • PubMed Abstract: 
  • Engagement of an extended β-sheet is a common substrate/inhibitor interaction at the active site of serine proteases and is an important feature of Laskowski mechanism inhibitors that present a substrate-like loop to a target protease. This loop is cleaved but subsequently relegated forming a stable inhibitor/protease complex ...

    Engagement of an extended β-sheet is a common substrate/inhibitor interaction at the active site of serine proteases and is an important feature of Laskowski mechanism inhibitors that present a substrate-like loop to a target protease. This loop is cleaved but subsequently relegated forming a stable inhibitor/protease complex. Laskowski inhibitors are ubiquitous in nature and are used extensively in serine protease inhibitor design. However, most studies concentrate on introducing new sidechain interactions rather than the direct contributions of the substrate-like β-sheet to enzyme inhibition. Here we report the crystal structure of an simplified β-sheet inhibitory motif within the Sunflower Trypsin Inhibitor (SFTI) in complex with trypsin. We show that the intramolecular hydrogen bond network of this SFTI variant (SFTI-TCTR) engages the inhibitor sidechains that would normally interact with a target protease, giving mainchain interactions a more prominent role in complex formation. Despite having reduced sidechain interactions, this SFTI variant is remarkably potent and inhibits a diverse range of serine proteases. Crystal structural analysis and molecular modelling of SFTI-TCTR complexes again indicates an interface dominated by β-sheet interactions, highlighting the importance of this motif and the adaptability of SFTI as a scaffold for inhibitor design.


    Organizational Affiliation

    School of Biomedical Sciences, Queensland University of Technology, Brisbane, Queensland, Australia.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
Cationic trypsinA223Bos taurusMutation(s): 0 
EC: 3.4.21.4
UniProt
Find proteins for P00760 (Bos taurus)
Explore P00760 
Go to UniProtKB:  P00760
Protein Feature View
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  • Reference Sequence
  • Find similar proteins by:  Sequence   |   Structure
Entity ID: 2
MoleculeChainsSequence LengthOrganismDetailsImage
Trypsin inhibitor 1B [auth I]14Helianthus annuusMutation(s): 0 
Gene Names: sfti1
UniProt
Find proteins for Q4GWU5 (Helianthus annuus)
Explore Q4GWU5 
Go to UniProtKB:  Q4GWU5
Protein Feature View
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  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.93 Å
  • R-Value Free: 0.158 
  • R-Value Work: 0.132 
  • R-Value Observed: 0.133 
  • Space Group: P 21 21 21
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 61.68α = 90
b = 63.24β = 90
c = 69.32γ = 90
Software Package:
Software NamePurpose
MOSFLMdata reduction
Aimlessdata scaling
PHENIXrefinement
PDB_EXTRACTdata extraction

Structure Validation

View Full Validation Report




Entry History & Funding Information

Deposition Data

  • Deposited Date: 2017-12-13 
  • Released Date: 2018-12-19 
  • Deposition Author(s): Riley, B.T., Chen, X.

Funding OrganizationLocationGrant Number
National Health & Medical Research CouncilAustralia1059410

Revision History  (Full details and data files)

  • Version 1.0: 2018-12-19
    Type: Initial release
  • Version 1.1: 2019-01-30
    Changes: Data collection, Database references