2VUE

Human serum albumin complexed with 4Z,15E-bilirubin-IX-alpha


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.42 Å
  • R-Value Free: 0.273 
  • R-Value Work: 0.218 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

Crystallographic Analysis of Human Serum Albumin Complexed with 4Z,15E-Bilirubin-Ixalpha.

Zunszain, P.A.Ghuman, J.Mcdonagh, A.F.Curry, S.

(2008) J.Mol.Biol. 381: 394

  • DOI: 10.1016/j.jmb.2008.06.016
  • Primary Citation of Related Structures:  2VUF

  • PubMed Abstract: 
  • Bilirubin, an insoluble yellow-orange pigment derived from heme catabolism, accumulates to toxic levels in individuals with impaired or immature liver function. The resulting jaundice may be managed with phototherapy to isomerize the biosynthetic 4Z, ...

    Bilirubin, an insoluble yellow-orange pigment derived from heme catabolism, accumulates to toxic levels in individuals with impaired or immature liver function. The resulting jaundice may be managed with phototherapy to isomerize the biosynthetic 4Z,15Z-bilirubin-IXalpha to more soluble and excretable isomers, such as 4Z,15E-bilirubin. Bilirubin and its configurational isomers are transported to the liver by human serum albumin (HSA) but their precise binding location(s) on the protein have yet to be determined. To investigate the molecular details of their interaction, we co-crystallised bilirubin with HSA. Strikingly, the crystal structure--determined to 2.42 A resolution--revealed the 4Z,15E-bilirubin-IXalpha isomer bound to an L-shaped pocket in sub-domain IB. We also determined the co-crystal structure of HSA complexed with fusidic acid, an antibiotic that competitively displaces bilirubin from the protein, and showed that it binds to the same pocket. These results provide the first crystal structure of a natural bilirubin pigment bound to serum albumin, challenge some of the present conceptions about HSA-bilirubin interactions, and provide a sound structural framework for finally resolving the long-standing question of where 4Z,15Z-bilirubin-IXalpha binds to the protein.


    Organizational Affiliation

    Biophysics Section, Blackett Laboratory, Imperial College, South Kensington Campus, Exhibition Road, London SW7 2AZ, UK.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
SERUM ALBUMIN
A, B
585Homo sapiensGene Names: ALB
Find proteins for P02768 (Homo sapiens)
Go to Gene View: ALB
Go to UniProtKB:  P02768
Small Molecules
Ligands 1 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
BLA
Query on BLA

Download SDF File 
Download CCD File 
A, B
BILIVERDINE IX ALPHA
C33 H34 N4 O6
GWZYPXHJIZCRAJ-SRVCBVSDSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.42 Å
  • R-Value Free: 0.273 
  • R-Value Work: 0.218 
  • Space Group: P 1
Unit Cell:
Length (Å)Angle (°)
a = 55.090α = 81.22
b = 55.540β = 90.70
c = 119.830γ = 65.42
Software Package:
Software NamePurpose
CNSphasing
CNSrefinement
SCALAdata scaling
MOSFLMdata reduction

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2008-06-17
    Type: Initial release
  • Version 1.1: 2011-05-08
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance