2B00

Crystal Structure of Porcine Pancreatic Phospholipase A2 in Complex with Glycocholate


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.85 Å
  • R-Value Free: 0.210 
  • R-Value Work: 0.186 

wwPDB Validation 3D Report Full Report


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, 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, ...

    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: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Phospholipase A2, major isoenzyme
A
124Sus scrofaGene Names: PLA2G1B
EC: 3.1.1.4
Find proteins for P00592 (Sus scrofa)
Go to Gene View: PLA2G1B
Go to UniProtKB:  P00592
Small Molecules
Ligands 2 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
GCH
Query on GCH

Download SDF File 
Download CCD File 
A
GLYCOCHOLIC ACID
N-CHOLYLGLYCINE
C26 H43 N O6
RFDAIACWWDREDC-FRVQLJSFSA-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: 1.85 Å
  • R-Value Free: 0.210 
  • R-Value Work: 0.186 
  • Space Group: P 31 2 1
Unit Cell:
Length (Å)Angle (°)
a = 69.577α = 90.00
b = 69.577β = 90.00
c = 64.184γ = 120.00
Software Package:
Software NamePurpose
CNSrefinement
AMoREphasing
SCALEPACKdata scaling
DENZOdata reduction

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

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