3F4X

Carbonic anhydrase inhibitors. Comparison of chlorthalidone and indapamide X-ray crystal structures in adducts with isozyme II: when three water molecules make the difference


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.9 Å
  • R-Value Free: 0.252 
  • R-Value Work: 0.199 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

Carbonic anhydrase inhibitors. Comparison of chlorthalidone and indapamide X-ray crystal structures in adducts with isozyme II: when three water molecules and the keto-enol tautomerism make the difference.

Temperini, C.Cecchi, A.Scozzafava, A.Supuran, C.T.

(2009) J.Med.Chem. 52: 322-328

  • DOI: 10.1021/jm801386n

  • PubMed Abstract: 
  • Thiazide diuretics inhibit all mammalian isoforms of carbonic anhydrase (CA, EC 4.2.1.1) with a different profile as compared to classical inhibitors. Acting as moderate-weak inhibitors of CA II and CA I, chlorthalidone and indapamide considerably in ...

    Thiazide diuretics inhibit all mammalian isoforms of carbonic anhydrase (CA, EC 4.2.1.1) with a different profile as compared to classical inhibitors. Acting as moderate-weak inhibitors of CA II and CA I, chlorthalidone and indapamide considerably inhibit other isozymes among the 16 CAs present in vertebrates. These compounds show a different behavior against CAs I and II, with chlorthalidone being 18.3 times more potent against CA II and 150 times more potent against CA I, as compared to indapamide. In the X-ray crystal structures of the CA II-chlorthalidone adduct three active site water molecules interacting with the inhibitor scaffold were observed that lack in the corresponding indapamide adduct. Chlorthalidone bound within the active site is in an enolic tautomeric form, with the OH moiety participating in two strong hydrogen bonds with Asn67 and a water molecule. This binding mode may be exploited for designing better CA II inhibitors.


    Organizational Affiliation

    Laboratorio di Chimica Bioinorganica, Universita degli Studi di Firenze, Rm. 188, Via della Lastruccia 3, I-50019 Sesto Fiorentino, Firenze, Italy.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Carbonic anhydrase 2
A
260Homo sapiensGene Names: CA2
EC: 4.2.1.1
Find proteins for P00918 (Homo sapiens)
Go to Gene View: CA2
Go to UniProtKB:  P00918
Small Molecules
Ligands 3 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
KLT
Query on KLT

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Download CCD File 
A
2-chloro-5-[(1S)-1-hydroxy-3-oxo-2H-isoindol-1-yl]benzenesulfonamide
chlorthalidone
C14 H11 Cl N2 O4 S
JIVPVXMEBJLZRO-AWEZNQCLSA-N
 Ligand Interaction
ZN
Query on ZN

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Download CCD File 
A
ZINC ION
Zn
PTFCDOFLOPIGGS-UHFFFAOYSA-N
 Ligand Interaction
HG
Query on HG

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Download CCD File 
A
MERCURY (II) ION
Hg
BQPIGGFYSBELGY-UHFFFAOYSA-N
 Ligand Interaction
External Ligand Annotations 
IDBinding Affinity (Sequence Identity %)
KLTKi: 138 - 138000 nM (100) BINDINGDB
KLTKi: 138 nM BINDINGMOAD
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.9 Å
  • R-Value Free: 0.252 
  • R-Value Work: 0.199 
  • Space Group: P 1 21 1
Unit Cell:
Length (Å)Angle (°)
a = 41.390α = 90.00
b = 42.140β = 104.29
c = 72.260γ = 90.00
Software Package:
Software NamePurpose
REFMACrefinement
CrysalisProdata collection
CrysalisProdata reduction
SCALEPACKdata scaling
AMoREphasing

Structure Validation

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Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2009-03-17
    Type: Initial release
  • Version 1.1: 2011-07-13
    Type: Version format compliance
  • Version 1.2: 2017-10-25
    Type: Refinement description