9EST

STRUCTURAL STUDY OF PORCINE PANCREATIC ELASTASE COMPLEXED WITH 7-AMINO-3-(2-BROMOETHOXY)-4-CHLOROISOCOUMARIN AS A NONREACTIVATABLE DOUBLY COVALENT ENZYME-INHIBITOR COMPLEX


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.9 Å

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

Structural study of porcine pancreatic elastase complexed with 7-amino-3-(2-bromoethoxy)-4-chloroisocoumarin as a nonreactivatable doubly covalent enzyme-inhibitor complex.

Vijayalakshmi, J.Meyer Jr., E.F.Kam, C.M.Powers, J.C.

(1991) Biochemistry 30: 2175-2183


  • PubMed Abstract: 
  • The complex of porcine pancreatic elastase (PPE) with 7-amino-3-(2-bromoethoxy)-4-chloroisocoumarin, a potent mechanism-based inhibitor, was crystallized and the crystal structure determined at 1.9-A resolution with a final R factor of 17.1%. The unb ...

    The complex of porcine pancreatic elastase (PPE) with 7-amino-3-(2-bromoethoxy)-4-chloroisocoumarin, a potent mechanism-based inhibitor, was crystallized and the crystal structure determined at 1.9-A resolution with a final R factor of 17.1%. The unbiased difference Fourier electron density map showed continuous density from O gamma of Ser 195 to the benzoyl carbonyl carbon atom and from N epsilon 2 of His 57 to the carbon atom at the 4-position of the isocoumarin ring in the inhibitor. This suggested unambiguously that the inhibitor was doubly covalently bound to the enzyme. It represents the first structural evidence for irreversible binding of an isocoumarin inhibitor to PPE through both Ser 195 and His 57 in the active site. The PPE-inhibitor complex is only partially activated in solution by hydroxylamine and confirms the existence of the doubly covalently bound complex along with the acyl enzyme. The benzoyl carbonyl oxygen atom of the inhibitor is not situated in the oxyanion hole formed by the amide (greater than NH) groups of Gly 193 and Ser 195. The complex is stabilized by the hydrogen-bonding interactions in the active site (from the N epsilon 2 of Gln 192 to the bromine atom in the inhibitor and the amino group at the 7-position of the isocoumarin ring to the carbonyl oxygen of Thr 41) and by van der Waals interactions. The inhibition rates of several 7-substituted 4-chloro-3-(bromoalkoxy)isocoumarins toward PPE were measured.(ABSTRACT TRUNCATED AT 250 WORDS)


    Related Citations: 
    • Reaction of Porcine Pancreatic Elastase with 7-Substituted 3-Alkoxy-4-Chloroisocoumarins: Design of Potent Inhibitors Using the Crystal Structure of the Complex Formed with 4-Chloro-3-Ethoxy-7-Guanidino-Isocoumarin
      Powers, J.C.,Oleksyszyn, J.,Narasimhan, S.L.,Kam, C.-M.,Radhakrishnan, R.,Meyerjunior, E.F.
      (1990) Biochemistry 29: 3108
    • Human Leukocyte and Porcine Pancreatic Elastase: X-Ray Crystal Structures, Mechanism, Substrate Specificity, and Mechanism-Based Inhibitors
      Bode, W.,Meyerjunior, E.F.,Powers, J.C.
      (1989) Biochemistry 28: 1951
    • Crystal Structures of the Complex of Porcine Pancreatic Elastase with Two Valine-Derived Benzoxazinone Inhibitors
      Radhakrishnan, R.,Presta, L.G.,Meyerjunior, E.F.,Wildonger, R.
      (1987) J.Mol.Biol. 198: 417
    • The 2.2-Angstrom Resolution X-Ray Crystal Structure of the Complex of Trypsin Inhibited by 4-Chloro-3-Ethoxy-7-Guanidinoisocoumarin: A Proposed Model of the Thrombin-Inhibitor Complex
      Chow, M.M.,Meyerjunior, E.F.,Bode, W.,Kam, C.-M.,Radhakrishnan, R.,Vijayalakshmi, J.,Powers, J.C.
      (1990) J.Am.Chem.Soc. 112: 7783
    • Stereospecific Reaction of 3-Methoxy-4-Chloro-7-Amino-Isocoumarin with Crystalline Porcine Pancreatic Elastase
      Meyerjunior, E.F.,Presta, L.G.,Radhakrishnan, R.
      (1985) J.Am.Chem.Soc. 107: 4091
    • Effect of the 7-Amino Substituent on the Inhibitory Potency of Mechanism-Based Isocoumarin Inhibitors for Porcine Pancreatic and Human Neutrophil Elastases: A 1.85-Angstroms X-Ray Structure of the Complex between Porcine Pancreatic Elastase and 7-[(N-Tosylphenylalanyl)Amino]-4-Chloro-3-Methoxyisocoumarin
      Hernandez, M.A.,Powers, J.C.,Glinski, J.,Oleksyszyn, J.,Vijayalakshmi, J.,Meyerjunior, E.F.
      (1992) J.Med.Chem. 35: 1121


    Organizational Affiliation

    Department of Bichemistry and Biophysics, Texas A&M University, College Station 77843-2128.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
PORCINE PANCREATIC ELASTASE
A
240Sus scrofaMutation(s): 0 
Gene Names: CELA1 (ELA1)
EC: 3.4.21.36
Find proteins for P00772 (Sus scrofa)
Go to Gene View: CELA1
Go to UniProtKB:  P00772
Small Molecules
Ligands 3 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
SO4
Query on SO4

Download SDF File 
Download CCD File 
A
SULFATE ION
O4 S
QAOWNCQODCNURD-UHFFFAOYSA-L
 Ligand Interaction
IBR
Query on IBR

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Download CCD File 
A
(2-BROMOETHYL)(2-'FORMYL-4'-AMINOPHENYL) ACETATE
C11 H12 Br N O3
SMKXVWWBCFWRMP-UHFFFAOYSA-N
 Ligand Interaction
CA
Query on CA

Download SDF File 
Download CCD File 
A
CALCIUM ION
Ca
BHPQYMZQTOCNFJ-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.9 Å
  • Space Group: P 21 21 21
Unit Cell:
Length (Å)Angle (°)
a = 51.130α = 90.00
b = 58.140β = 90.00
c = 75.450γ = 90.00
Software Package:
Software NamePurpose
TNTrefinement

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 1994-01-31
    Type: Initial release
  • Version 1.1: 2008-03-03
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance