3D5E

Crystal structure of human plasma platelet activating factor acetylhydrolase covalently inhibited by paraoxon


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.1 Å
  • R-Value Free: 0.261 
  • R-Value Work: 0.204 

wwPDB Validation 3D Report Full Report


This is version 1.1 of the entry. See complete history

Literature

Crystal Structure of Human Plasma Platelet-activating Factor Acetylhydrolase: STRUCTURAL IMPLICATION TO LIPOPROTEIN BINDING AND CATALYSIS.

Samanta, U.Bahnson, B.J.

(2008) J.Biol.Chem. 283: 31617-31624

  • DOI: 10.1074/jbc.M804750200
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 
  • Human plasma platelet-activating factor (PAF) acetylhydrolase functions by reducing PAF levels as a general anti-inflammatory scavenger and is linked to anaphylactic shock, asthma, and allergic reactions. The enzyme has also been implicated in hydrol ...

    Human plasma platelet-activating factor (PAF) acetylhydrolase functions by reducing PAF levels as a general anti-inflammatory scavenger and is linked to anaphylactic shock, asthma, and allergic reactions. The enzyme has also been implicated in hydrolytic activities of other pro-inflammatory agents, such as sn-2 oxidatively fragmented phospholipids. This plasma enzyme is tightly bound to low and high density lipoprotein particles and is also referred to as lipoprotein-associated phospholipase A2. The crystal structure of this enzyme has been solved from x-ray diffraction data collected to a resolution of 1.5 angstroms. It has a classic lipase alpha/beta-hydrolase fold, and it contains a catalytic triad of Ser273, His351, and Asp296. Two clusters of hydrophobic residues define the probable interface-binding region, and a prediction is given of how the enzyme is bound to lipoproteins. Additionally, an acidic patch of 10 carboxylate residues and a neighboring basic patch of three residues are suggested to play a role in high density lipoprotein/low density lipoprotein partitioning. A crystal structure is also presented of PAF acetylhydrolase reacted with the organophosphate compound paraoxon via its active site Ser273. The resulting diethyl phosphoryl complex was used to model the tetrahedral intermediate of the substrate PAF to the active site. The model of interface binding begins to explain the known specificity of lipoprotein-bound substrates and how the active site can be both close to the hydrophobic-hydrophilic interface and at the same time be accessible to the aqueous phase.


    Organizational Affiliation

    Department of Chemistry & Biochemistry, University of Delaware, Newark, Delaware 19716, USA.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Platelet-activating factor acetylhydrolase
A, B
383Homo sapiensMutation(s): 0 
Gene Names: PLA2G7 (PAFAH)
EC: 3.1.1.47
Find proteins for Q13093 (Homo sapiens)
Go to Gene View: PLA2G7
Go to UniProtKB:  Q13093
Small Molecules
Ligands 2 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
FMT
Query on FMT

Download SDF File 
Download CCD File 
A, B
FORMIC ACID
C H2 O2
BDAGIHXWWSANSR-UHFFFAOYSA-N
 Ligand Interaction
DEP
Query on DEP

Download SDF File 
Download CCD File 
A, B
DIETHYL PHOSPHONATE
C4 H11 O3 P
MJUJXFBTEFXVKU-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.1 Å
  • R-Value Free: 0.261 
  • R-Value Work: 0.204 
  • Space Group: C 1 2 1
Unit Cell:
Length (Å)Angle (°)
a = 117.213α = 90.00
b = 78.696β = 101.61
c = 97.340γ = 90.00
Software Package:
Software NamePurpose
HKL-2000data scaling
MOLREPphasing
REFMACrefinement
HKL-2000data reduction
REFMACphasing

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2008-09-09
    Type: Initial release
  • Version 1.1: 2011-07-13
    Type: Version format compliance