2B04

Crystal Structure of Porcine Pancreatic Phospholipase A2 in Complex with Glycochenodeoxycholate


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.50 Å
  • R-Value Free: 0.244 
  • R-Value Work: 0.211 

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This is version 1.2 of the entry. See complete history


Literature

Structural basis for bile salt inhibition of pancreatic phospholipase A2.

Pan, Y.H.Bahnson, B.J.

(2007) J Mol Biol 369: 439-450

  • DOI: 10.1016/j.jmb.2007.03.034
  • Primary Citation of Related Structures:  
    2AZY, 2AZZ, 2B00, 2B01, 2B03, 2B04

  • PubMed Abstract: 
  • Bile salt interactions with phospholipid monolayers of fat emulsions are known to regulate the actions of gastrointestinal lipolytic enzymes in order to control the uptake of dietary fat. Specifically, on the lipid/aqueous interface of fat emulsions, the anionic portions of amphipathic bile salts have been thought to interact with and activate the enzyme group-IB phospholipase A2 (PLA2) derived from the pancreas ...

    Bile salt interactions with phospholipid monolayers of fat emulsions are known to regulate the actions of gastrointestinal lipolytic enzymes in order to control the uptake of dietary fat. Specifically, on the lipid/aqueous interface of fat emulsions, the anionic portions of amphipathic bile salts have been thought to interact with and activate the enzyme group-IB phospholipase A2 (PLA2) derived from the pancreas. To explore this regulatory process, we have determined the crystal structures of the complexes of pancreatic PLA2 with the naturally occurring bile salts: cholate, glycocholate, taurocholate, glycochenodeoxycholate, and taurochenodeoxycholate. The five PLA2-bile salt complexes each result in a partly occluded active site, and the resulting ligand binding displays specific hydrogen bonding interactions and extensive hydrophobic packing. The amphipathic bile salts are bound to PLA2 with their polar hydroxyl and sulfate/carboxy groups oriented away from the enzyme's hydrophobic core. The impaired catalytic and interface binding functions implied by these structures provide a basis for the previous numerous observations of a biphasic dependence of the rate of PLA2 catalyzed hydrolysis of zwitterionic glycerophospholipids in the presence of bile salts. The rising or activation phase is consistent with enhanced binding and activation of the bound PLA2 by the bile salt induced anionic charge in a zwitterionic interface. The falling or inhibitory phase can be explained by the formation of a catalytically inert stoichiometric complex between PLA2 and any bile salts in which it forms a stable complex. The model provides new insight into the regulatory role that specific PLA2-bile salt interactions are likely to play in fat metabolism.


    Organizational Affiliation

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



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
Phospholipase A2, major isoenzymeA124Sus scrofaMutation(s): 0 
Gene Names: PLA2G1B
EC: 3.1.1.4
UniProt
Find proteins for P00592 (Sus scrofa)
Explore P00592 
Go to UniProtKB:  P00592
Protein Feature View
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  • Reference Sequence
Small Molecules
Ligands 3 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
CHO (Subject of Investigation/LOI)
Query on CHO

Download Ideal Coordinates CCD File 
B [auth A]GLYCOCHENODEOXYCHOLIC ACID
C26 H43 N O5
GHCZAUBVMUEKKP-GYPHWSFCSA-N
 Ligand Interaction
CA
Query on CA

Download Ideal Coordinates CCD File 
C [auth A], D [auth A], E [auth A]CALCIUM ION
Ca
BHPQYMZQTOCNFJ-UHFFFAOYSA-N
 Ligand Interaction
CL
Query on CL

Download Ideal Coordinates CCD File 
F [auth A]CHLORIDE ION
Cl
VEXZGXHMUGYJMC-UHFFFAOYSA-M
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.50 Å
  • R-Value Free: 0.244 
  • R-Value Work: 0.211 
  • Space Group: P 31 2 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 69.156α = 90
b = 69.156β = 90
c = 67.043γ = 120
Software Package:
Software NamePurpose
CNSrefinement
DENZOdata reduction
SCALEPACKdata scaling
AMoREphasing

Structure Validation

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Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2006-11-14
    Type: Initial release
  • Version 1.1: 2008-05-01
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Derived calculations, Version format compliance