1L6L

Structures of Apolipoprotein A-II and a Lipid Surrogate Complex Provide Insights into Apolipoprotein-Lipid Interactions


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.3 Å
  • R-Value Free: 0.238 
  • R-Value Work: 0.198 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

Structures of apolipoprotein A-II and a lipid-surrogate complex provide insights into apolipoprotein-lipid interactions.

Kumar, M.S.Carson, M.Hussain, M.M.Murthy, H.M.

(2002) Biochemistry 41: 11681-11691

  • Primary Citation of Related Structures:  1L6K, 2OU1

  • PubMed Abstract: 
  • Apolipoproteins A-I and A-II form the major protein constituents of high-density lipid particles (HDL), the concentration of which is inversely correlated with the frequency of heart disease in humans. Although the physiological role of apolipoprotei ...

    Apolipoproteins A-I and A-II form the major protein constituents of high-density lipid particles (HDL), the concentration of which is inversely correlated with the frequency of heart disease in humans. Although the physiological role of apolipoprotein A-II is unclear, evidence for its involvement in free fatty acid metabolism in mice has recently been obtained. Currently, the best characterized activity of apolipoprotein A-II is its potent antagonism of the anti-atherogenic and anti-inflammatory activities of apolipoprotein A-I, probably due to its competition with the latter for lipid acyl side chains in HDL. Many interactions of apolipoprotein A-I with enzymes and proteins involved in reverse cholesterol transport and HDL maturation are mediated by lipid-bound protein. The structural bases of interaction with lipids are expected to be common to exchangeable apolipoproteins and attributable to amphipathic alpha-helices present in each of them. Thus, characterization of apolipoprotein-lipid interactions in any apolipoprotein is likely to provide information that is applicable to the entire class. We report structures of human apolipoprotein A-II and its complex with beta-octyl glucoside, a widely used lipid surrogate. The former shows that disulfide-linked dimers of apolipoprotein A-II form amphipathic alpha-helices which aggregate into tetramers. Dramatic changes, observed in the presence of beta-octyl glucoside, might provide clues to the structural basis for its antagonism of apolipoprotein A-I. Additionally, excursions of individual molecules of apolipoprotein A-II from a common helical architecture in both structures indicate that lipid-bound apolipoproteins are likely to have an ensemble of related conformations. These structures provide the first experimental paradigm for description of apolipoprotein-lipid interactions at the atomic level.


    Organizational Affiliation

    Center for Biophysical Sciences and Engineering, University of Alabama at Birmingham, 1530 3rd Avenue South, Birmingham, AL 35294, USA.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Apolipoprotein A-II
A, B, C, D, E, F, G, H, I, J, K, L, M, N, P, Q, S, T, U, V, W, X, Y, Z, 1, 2, 3, 4, 5, 6, 7, 8
77Homo sapiensGene Names: APOA2
Find proteins for P02652 (Homo sapiens)
Go to Gene View: APOA2
Go to UniProtKB:  P02652
Small Molecules
Ligands 1 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
BOG
Query on BOG

Download SDF File 
Download CCD File 
1, 2, 3, 4, 5, 6, 7, 8, A, B, C, D, E, F, G, H, I, J, K, L, M, N, P, Q, S, T, U, W, X, Y, Z
B-OCTYLGLUCOSIDE
C14 H28 O6
HEGSGKPQLMEBJL-RKQHYHRCSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.3 Å
  • R-Value Free: 0.238 
  • R-Value Work: 0.198 
  • Space Group: P 1
Unit Cell:
Length (Å)Angle (°)
a = 114.400α = 90.70
b = 115.900β = 96.20
c = 126.600γ = 93.50
Software Package:
Software NamePurpose
XDSdata reduction
XDSdata scaling
CNSrefinement
SOLVEphasing
SIEMENSdata reduction
Siemensdata collection

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2002-10-02
    Type: Initial release
  • Version 1.1: 2008-04-28
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance