3KGQ

Carboxypeptidase A liganded to an organic small-molecule: conformational changes


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.7 Å
  • R-Value Free: 0.204 
  • R-Value Work: 0.180 

wwPDB Validation 3D Report Full Report


This is version 1.4 of the entry. See complete history

Literature

Structural and Functional Analysis of the Complex between Citrate and the Zinc Peptidase Carboxypeptidase A

Fernandez, D.Boix, E.Pallares, I.Aviles, F.X.Vendrell, J.

(2011) Enzyme Res 2011: 128676-128676

  • DOI: 10.4061/2011/128676

  • PubMed Abstract: 
  • A high-resolution carboxypeptidase-Zn(2+)-citrate complex was studied by X-ray diffraction and enzyme kinetics for the first time. The citrate molecule acts as a competitive inhibitor of this benchmark zinc-dependent peptidase, chelating the catalyti ...

    A high-resolution carboxypeptidase-Zn(2+)-citrate complex was studied by X-ray diffraction and enzyme kinetics for the first time. The citrate molecule acts as a competitive inhibitor of this benchmark zinc-dependent peptidase, chelating the catalytic zinc ion in the active site of the enzyme and inducing a conformational change such that carboxypeptidase adopts the conformation expected to occur by substrate binding. Citrate adopts an extended conformation with half of the molecule facing the zinc ion, while the other half is docked in the S1' hydrophobic specificity pocket of the enzyme, in contrast with the binding mode expected for a substrate like phenylalanine or a peptidomimetic inhibitor like benzylsuccinic acid. Combined structural and enzymatic analysis describes the characteristics of the binding of this ligand that, acting against physiologically relevant zinc-dependent proteases, may serve as a general model in the design of new drug-protecting molecules for the oral delivery of drugs of peptide origin.


    Organizational Affiliation

    Departament de Bioquímica i Biologia Molecular, Facultat de Biociències, Universitat Autònoma de Barcelona, 08193 Bellaterra, Spain.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Carboxypeptidase A1
A
309Bos taurusMutation(s): 0 
Gene Names: CPA1 (CPA)
EC: 3.4.17.1
Find proteins for P00730 (Bos taurus)
Go to Gene View: CPA1
Go to UniProtKB:  P00730
Small Molecules
Ligands 6 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
ZN
Query on ZN

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A
ZINC ION
Zn
PTFCDOFLOPIGGS-UHFFFAOYSA-N
 Ligand Interaction
NA
Query on NA

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A
SODIUM ION
Na
FKNQFGJONOIPTF-UHFFFAOYSA-N
 Ligand Interaction
CIT
Query on CIT

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A
CITRIC ACID
C6 H8 O7
KRKNYBCHXYNGOX-UHFFFAOYSA-N
 Ligand Interaction
ACN
Query on ACN

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A
ACETONE
C3 H6 O
CSCPPACGZOOCGX-UHFFFAOYSA-N
 Ligand Interaction
FMT
Query on FMT

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A
FORMIC ACID
C H2 O2
BDAGIHXWWSANSR-UHFFFAOYSA-N
 Ligand Interaction
GOL
Query on GOL

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A
GLYCEROL
GLYCERIN; PROPANE-1,2,3-TRIOL
C3 H8 O3
PEDCQBHIVMGVHV-UHFFFAOYSA-N
 Ligand Interaction
External Ligand Annotations 
IDBinding Affinity (Sequence Identity %)
CITKi: 5000000 nM PDBBIND
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.7 Å
  • R-Value Free: 0.204 
  • R-Value Work: 0.180 
  • Space Group: P 1 21 1
Unit Cell:
Length (Å)Angle (°)
a = 40.604α = 90.00
b = 57.006β = 102.04
c = 60.604γ = 90.00
Software Package:
Software NamePurpose
PHASERphasing
SCALAdata scaling
AUTOMARdata reduction
REFMACrefinement
PDB_EXTRACTdata extraction
MAR345dtbdata collection

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2010-10-27
    Type: Initial release
  • Version 1.1: 2011-07-13
    Type: Version format compliance
  • Version 1.2: 2011-08-03
    Type: Database references
  • Version 1.3: 2013-06-12
    Type: Database references
  • Version 1.4: 2017-10-04
    Type: Advisory, Data collection