1XQ0

Structure of human carbonic anhydrase II with 4-[(3-bromo-4-O-sulfamoylbenzyl)(4-cyanophenyl)amino]-4H-[1,2,4]-triazole


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.76 Å
  • R-Value Free: 0.209 
  • R-Value Work: 0.194 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

First Crystal Structures of Human Carbonic Anhydrase II in Complex with Dual Aromatase-Steroid Sulfatase Inhibitors(,)

Lloyd, M.D.Thiyagarajan, N.Ho, Y.T.Woo, L.W.L.Sutcliffe, O.B.Purohit, A.Reed, M.J.Acharya, K.R.Potter, B.V.L.

(2005) Biochemistry 44: 6858-6866

  • DOI: 10.1021/bi047692e
  • Primary Citation of Related Structures:  1XPZ

  • PubMed Abstract: 
  • Carbonic anhydrase (CA) catalyzes the reversible hydration of carbon dioxide to hydrogen carbonate. The role of CA in maintaining pH balance has made it an attractive drug target for the treatment of cancer, and it has recently been implicated in the ...

    Carbonic anhydrase (CA) catalyzes the reversible hydration of carbon dioxide to hydrogen carbonate. The role of CA in maintaining pH balance has made it an attractive drug target for the treatment of cancer, and it has recently been implicated in the delivery of sulfamate-containing drugs. With the acceptance of steroid sulfatase as a target for hormone-dependent cancer, novel dual aromatase-steroid sulfatase inhibitors (DASIs) containing a sulfamate group are now being developed. In this study, we show that CA II is potently inhibited by several members of this class of inhibitor. The structures of CA II complexed with 4-[(4-O-sulfamoylbenzyl)(4-cyanophenyl)amino]-4H-[1,2,4]triazole (K(D) = 84 +/- 5 nM) and 4-[(3-bromo-4-O-sulfamoylbenzyl)(4-cyanophenyl)amino]-4H-[1,2,4]triazole (K(D) = 454 +/- 29 nM) are reported to 2.02 and 1.76 A, respectively. Both inhibitors ligate to the active site zinc(II) atom via their sulfamate nitrogen, while the rest of the molecule is contained within the hydrophobic binding pocket. Key protein residues include Val-121, Phe-131, Val-135, Val-143, Leu-141, Leu-198, Pro-202, and Leu-204. Despite being structurally similar, the two ligands experience different types of binding particularly in the sulfamate-containing aromatic ring and the opposite geometric arrangement of the triazole and cyanophenyl groups around the configurationally invertible central nitrogen atom. Small changes in inhibitor structure can cause large changes in binding to CA II, and this underlines the importance of structure-based drug design with this enzyme and other isoforms relevant to potential anticancer therapy. Moreover, these results underpin the idea that binding to erythrocyte CA II may be a general method of stabilizing and delivering sulfamate-based drugs in vivo.


    Organizational Affiliation

    Medicinal Chemistry, Department of Pharmacy and Pharmacology, University of Bath, Claverton Down, Bath BA2 7AY, United Kingdom. M.D.Lloyd@bath.ac.uk




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Carbonic anhydrase II
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 2 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
ZN
Query on ZN

Download SDF File 
Download CCD File 
A
ZINC ION
Zn
PTFCDOFLOPIGGS-UHFFFAOYSA-N
 Ligand Interaction
4TR
Query on 4TR

Download SDF File 
Download CCD File 
A
2-BROMO-4-{[(4-CYANOPHENYL)(4H-1,2,4-TRIAZOL-4-YL)AMINO]METHYL}PHENYL SULFAMATE
4-[(3-BROMO-4-O-SULFAMOYLBENZYL)(4-CYANOPHENYL)AMINO]-4H-[1,2,4]-TRIAZOLE
C16 H13 Br N6 O3 S
GHDKYBCUDPSXGJ-UHFFFAOYSA-N
 Ligand Interaction
External Ligand Annotations 
IDBinding Affinity (Sequence Identity %)
4TRIC50: 137 nM (100) BINDINGDB
4TRKd: 454 nM BINDINGMOAD
4TRKd: 454 nM PDBBIND
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.76 Å
  • R-Value Free: 0.209 
  • R-Value Work: 0.194 
  • Space Group: P 21 21 21
Unit Cell:
Length (Å)Angle (°)
a = 42.551α = 90.00
b = 72.656β = 90.00
c = 75.103γ = 90.00
Software Package:
Software NamePurpose
SCALEPACKdata scaling
DENZOdata reduction
CNSrefinement
CNSphasing

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2005-05-17
    Type: Initial release
  • Version 1.1: 2008-04-30
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance