1BZM

DRUG-PROTEIN INTERACTIONS: STRUCTURE OF SULFONAMIDE DRUG COMPLEXED WITH HUMAN CARBONIC ANHYDRASE I


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2 Å

wwPDB Validation 3D Report Full Report


This is version 1.4 of the entry. See complete history

Literature

Drug-protein interactions. Refined structures of three sulfonamide drug complexes of human carbonic anhydrase I enzyme.

Chakravarty, S.Kannan, K.K.

(1994) J.Mol.Biol. 243: 298-309

  • DOI: 10.1006/jmbi.1994.1655
  • Primary Citation of Related Structures:  1AZM, 1CZM

  • PubMed Abstract: 
  • N-unsubstituted sulfonamide drugs are widely used for opthalmic disorders. Inhibition of carbonic anhydrase enzyme is believed to be the chief reason for their therapeutic effects. Structures of three such sulfonamide drugs complexed to human carboni ...

    N-unsubstituted sulfonamide drugs are widely used for opthalmic disorders. Inhibition of carbonic anhydrase enzyme is believed to be the chief reason for their therapeutic effects. Structures of three such sulfonamide drugs complexed to human carbonic anhydrase I enzyme (HCAI) refined crystallographically at 2 A resolution are reported here. The drug molecules are all bound in the active site of the enzyme, but among themselves show differences in the orientations of the sulfamido groups interacting with the essential zinc ion in the active site. The activity linked solvent molecule coordinated to zinc in the native enzyme is displaced by all the three sulfonamides. The active site loop of Leu198, Thr199 and His200 has been identified to be important for binding of the drug molecules due to their appreciable atomic displacements and intra-molecular hydrogen bonds arising out of their interactions with the sulfonamides. These interactions along with active site charge requirements are proposed to be responsible for the orientational differences of the sulfamido groups and also for differences in the inhibitory powers of the drugs. A hydrogen bond network involving solvent molecules and active site residues His200 and His67 amongst others in the native enzyme, is disrupted upon binding of methazolamide but not in the other two sulfonamides. This is the first crystallographic evidence of the possible involvement of His200 in the inhibition of HCAI. An important role of Thr199 in distinguishing between the substrate and inhibitor binding modes of HCO3- to the enzyme at high pH is also inferred.


    Related Citations: 
    • Structure and Function of Carbonic Anhydrase: Comparative Studies of Sulphonamide Binding to Human Erythrocyte Carbonic Anhydrases B and C
      Kannan, K.K.,Vaara, I.,Notstrand, B.,Lovgren, S.,Borell, A.,Fridborg, K.,Petef, M.
      (1977) Drug Action at the Molecular Level --: 73
    • Drug Protein Interaction at the Molecular Level: A Study of Sulphonamide Carbonic Anhydrase Complexes
      Chakravarty, S.,Yadava, V.S.,Kumar, V.,Kannan, K.K.
      (1985) J.Biosci. 8: 491


    Organizational Affiliation

    Solid State Physics Division, Bhabha Atomic Research Centre, Bombay, India.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
CARBONIC ANHYDRASE I
A
260Homo sapiensGene Names: CA1
EC: 4.2.1.1
Find proteins for P00915 (Homo sapiens)
Go to Gene View: CA1
Go to UniProtKB:  P00915
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
MZM
Query on MZM

Download SDF File 
Download CCD File 
A
N-(3-methyl-5-sulfamoyl-1,3,4-thiadiazol-2(3H)-ylidene)acetamide
Methazolamide
C5 H8 N4 O3 S2
FLOSMHQXBMRNHR-DAXSKMNVSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2 Å
  • Space Group: P 21 21 21
Unit Cell:
Length (Å)Angle (°)
a = 81.850α = 90.00
b = 75.310β = 90.00
c = 37.760γ = 90.00
Software Package:
Software NamePurpose
PROTEINrefinement

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 1994-04-30
    Type: Initial release
  • Version 1.1: 2008-03-03
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance
  • Version 1.3: 2016-04-06
    Type: Non-polymer description
  • Version 1.4: 2017-11-29
    Type: Derived calculations, Other