2F14

Tne Crystal Structure of the Human Carbonic Anhydrase II in Complex with a Fluorescent Inhibitor


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.71 Å
  • R-Value Free: 0.202 
  • R-Value Work: 0.172 

wwPDB Validation 3D Report Full Report


This is version 1.3 of the entry. See complete history

Literature

Carbonic anhydrase inhibitors: X-ray and molecular modeling study for the interaction of a fluorescent antitumor sulfonamide with isozyme II and IX.

Alterio, V.Vitale, R.M.Monti, S.M.Pedone, C.Scozzafava, A.Cecchi, A.De Simone, G.Supuran, C.T.

(2006) J.Am.Chem.Soc. 128: 8329-8335

  • DOI: 10.1021/ja061574s

  • PubMed Abstract: 
  • The X-ray crystal structure of the fluorescent antitumor sulfonamide carbonic anhydrase (CA, EC, 4.2.1.1) inhibitor (4-sulfamoylphenylethyl)thioureido fluorescein (1) in complex with the cytosolic isoform hCA II is reported, together with a modeling ...

    The X-ray crystal structure of the fluorescent antitumor sulfonamide carbonic anhydrase (CA, EC, 4.2.1.1) inhibitor (4-sulfamoylphenylethyl)thioureido fluorescein (1) in complex with the cytosolic isoform hCA II is reported, together with a modeling study of the adduct of 1 with the tumor-associated isoform hCA IX. Its binding to hCA II is similar to that of other benzesulfonamides, with the ionized sulfonamide coordinated to the Zn2+ ion within the enzyme active site, and also participating in a network of hydrogen bonds with residues Thr199 and Glu106. The scaffold of 1 did not establish polar interactions within the enzyme active site but made hydrophobic contacts (<4.5 A) with Gln92, Val121, Phe131, Val135, Leu198, Thr199, Thr200, and Pro202. The substituted 3-carboxy-amino-phenyl functionality was at van der Waals distance from Phe131, Gly132, and Val135. The bulky tricyclic fluorescein moiety was located at the rim of the active site, on the protein surface, and strongly interacted with the alpha-helix formed by residues Asp130-Val135. All these interactions were preserved in the hCA IX-1 adduct, but the carbonyl moiety of the fluorescein tail of 1 participates in a strong hydrogen bond with the guanidine moiety of Arg130, an amino acid characteristic of the hCA IX active site. This may account for the roughly 2 times higher affinity of 1 for hCA IX over hCA II and may explain why in vivo the compound specifically accumulates only in hypoxic tumors overexpressing CA IX and not in the normal tissues. The compound is in clinical studies as an imaging tool for acute hypoxic tumors.


    Organizational Affiliation

    Istituto di Biostrutture e Bioimmagini-CNR, via Mezzocannone 16, 80134 Naples, Italy.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Carbonic anhydrase 2
A
259Homo 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 4 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
FL1
Query on FL1

Download SDF File 
Download CCD File 
A
5-{[({2-[4-(AMINOSULFONYL)PHENYL]ETHYL}AMINO)CARBONOTHIOYL]AMINO}-2-(6-HYDROXY-3-OXO-3H-XANTHEN-9-YL)BENZOIC ACID
(4-SULFAMOYLPHENYLETHYLTHIOUREIDO)FLUORESCEIN
C29 H23 N3 O7 S2
ZXJGFVGTIKDQMI-UHFFFAOYSA-N
 Ligand Interaction
ZN
Query on ZN

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

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Download CCD File 
A
GLYCEROL
GLYCERIN; PROPANE-1,2,3-TRIOL
C3 H8 O3
PEDCQBHIVMGVHV-UHFFFAOYSA-N
 Ligand Interaction
HGB
Query on HGB

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Download CCD File 
A
4-(HYDROXYMERCURY)BENZOIC ACID
C7 H6 Hg O3
WMHRYLDWLOGHSG-UHFFFAOYSA-M
 Ligand Interaction
External Ligand Annotations 
IDBinding Affinity (Sequence Identity %)
FL1Ki: 45 nM BINDINGMOAD
FL1Kd: 0.64 nM PDBBIND
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.71 Å
  • R-Value Free: 0.202 
  • R-Value Work: 0.172 
  • Space Group: P 1 21 1
Unit Cell:
Length (Å)Angle (°)
a = 42.260α = 90.00
b = 41.600β = 104.57
c = 72.220γ = 90.00
Software Package:
Software NamePurpose
MAR345data collection
SCALEPACKdata scaling
CNSrefinement
CNSphasing

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2006-10-24
    Type: Initial release
  • Version 1.1: 2008-05-01
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Non-polymer description, Version format compliance
  • Version 1.3: 2017-10-18
    Type: Advisory, Refinement description