Crystal structure of human Prostasin complexed to 4-guanidinobenzoic acid

Experimental Data Snapshot

  • Resolution: 2.00 Å
  • R-Value Free: 0.225 
  • R-Value Work: 0.173 
  • R-Value Observed: 0.176 

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Structure of human prostasin, a target for the regulation of hypertension.

Rickert, K.W.Kelley, P.Byrne, N.J.Diehl, R.E.Hall, D.L.Montalvo, A.M.Reid, J.C.Shipman, J.M.Thomas, B.W.Munshi, S.K.Darke, P.L.Su, H.P.

(2008) J Biol Chem 283: 34864-34872

  • DOI: https://doi.org/10.1074/jbc.M805262200
  • Primary Citation of Related Structures:  
    3DFJ, 3DFL

  • PubMed Abstract: 

    Prostasin (also called channel activating protease-1 (CAP1)) is an extracellular serine protease implicated in the modulation of fluid and electrolyte regulation via proteolysis of the epithelial sodium channel. Several disease states, particularly hypertension, can be affected by modulation of epithelial sodium channel activity. Thus, understanding the biochemical function of prostasin and developing specific agents to inhibit its activity could have a significant impact on a widespread disease. We report the expression of the prostasin proenzyme in Escherichia coli as insoluble inclusion bodies, refolding and activating via proteolytic removal of the N-terminal propeptide. The refolded and activated enzyme was shown to be pure and monomeric, with kinetic characteristics very similar to prostasin expressed from eukaryotic systems. Active prostasin was crystallized, and the structure was determined to 1.45 A resolution. These apoprotein crystals were soaked with nafamostat, allowing the structure of the inhibited acyl-enzyme intermediate structure to be determined to 2.0 A resolution. Comparison of the inhibited and apoprotein forms of prostasin suggest a mechanism of regulation through stabilization of a loop which interferes with substrate recognition.

  • Organizational Affiliation

    Department of Global Structural Biology, Merck Research Laboratories, West Point, Pennsylvania 19486, USA. keith_rickert@merck.com

Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Prostasin263Homo sapiensMutation(s): 2 
Gene Names: PRSS8
EC: 3.4.21
UniProt & NIH Common Fund Data Resources
Find proteins for Q16651 (Homo sapiens)
Explore Q16651 
Go to UniProtKB:  Q16651
GTEx:  ENSG00000052344 
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupQ16651
Sequence Annotations
  • Reference Sequence
Small Molecules
Ligands 1 Unique
IDChains Name / Formula / InChI Key2D Diagram3D Interactions
Query on GBS

Download Ideal Coordinates CCD File 
B [auth A]4-carbamimidamidobenzoic acid
C8 H9 N3 O2
Experimental Data & Validation

Experimental Data

  • Resolution: 2.00 Å
  • R-Value Free: 0.225 
  • R-Value Work: 0.173 
  • R-Value Observed: 0.176 
  • Space Group: P 21 21 21
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 53.498α = 90
b = 54.846β = 90
c = 83.279γ = 90
Software Package:
Software NamePurpose
DENZOdata reduction
SCALEPACKdata scaling
PDB_EXTRACTdata extraction

Structure Validation

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Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2008-10-14
    Type: Initial release
  • Version 1.1: 2011-07-13
    Changes: Version format compliance
  • Version 1.2: 2017-10-25
    Changes: Refinement description
  • Version 2.0: 2021-10-20
    Changes: Atomic model, Database references, Derived calculations, Structure summary