5MUE

Self-assembled alpha-Tocopherol Transfer Protein Nanoparticles Promote Vitamin E Delivery Across an Endothelial Barrier

Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.40 Å
  • R-Value Free: 0.215 
  • R-Value Work: 0.182 
  • R-Value Observed: 0.184 

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Literature

Self-assembled alpha-Tocopherol Transfer Protein Nanoparticles Promote Vitamin E Delivery Across an Endothelial Barrier.

Aeschimann, W., Staats, S., Kammer, S., Olieric, N., Jeckelmann, J.M., Fotiadis, D., Netscher, T., Rimbach, G., Cascella, M., Stocker, A.

(2017) Sci Rep 7: 4970-4970

  • DOI: 10.1038/s41598-017-05148-9
  • Primary Citation of Related Structures:  
    5MUE, 5MUG

  • PubMed Abstract: 

    • Vitamin E is one of the most important natural antioxidants, protecting polyunsaturated fatty acids in the membranes of cells. Among different chemical isoforms assimilated from dietary regimes, RRR-α-tocopherol is the only one retained in higher animals ...

    Vitamin E is one of the most important natural antioxidants, protecting polyunsaturated fatty acids in the membranes of cells. Among different chemical isoforms assimilated from dietary regimes, RRR-α-tocopherol is the only one retained in higher animals. This is possible thanks to α-Tocopherol Transfer Protein (α-TTP), which extracts α-tocopherol from endosomal compartments in liver cells, facilitating its distribution into the body. Here we show that, upon binding to its substrate, α-TTP acquires tendency to aggregation into thermodynamically stable high molecular weight oligomers. Determination of the structure of such aggregates by X-ray crystallography revealed a spheroidal particle formed by 24 protein monomers. Oligomerization is triggered by refolding of the N-terminus. Experiments with cultured cell monolayers demonstrate that the same oligomers are efficiently transported through an endothelial barrier (HUVEC) and not through an epithelial one (Caco-2). Discovery of a human endogenous transport protein with intrinsic capability of crossing endothelial tissues opens to new ways of drug delivery into the brain or other tissues protected by endothelial barriers.

    Organizational Affiliation: 

    University of Bern, Department of Chemistry and Biochemistry, Bern, Switzerland. achim.stocker@dcb.unibe.ch.



Macromolecules
Find similar proteins by: 
(by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
Alpha-tocopherol transfer proteinA228Homo sapiensMutation(s): 0 
Gene Names: TTPA, TPP1
UniProt & NIH Common Fund Data Resources
Find proteins for P49638 (Homo sapiens)
Explore P49638 
Go to UniProtKB:  P49638
PHAROS:  P49638
GTEx:  ENSG00000137561 
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP49638
Protein Feature View
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  • Reference Sequence
Small Molecules
Ligands 4 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
VIV
Query on VIV
Download Ideal Coordinates CCD File 
C [auth A](2R)-2,5,7,8-TETRAMETHYL-2-[(4R,8R)-4,8,12-TRIMETHYLTRIDECYL]CHROMAN-6-OL
C29 H50 O2
GVJHHUAWPYXKBD-IEOSBIPESA-N		 Ligand Interaction
SO4
Query on SO4
Download Ideal Coordinates CCD File 
B [auth A]SULFATE ION
O4 S
QAOWNCQODCNURD-UHFFFAOYSA-L		 Ligand Interaction
ETA
Query on ETA
Download Ideal Coordinates CCD File 
E [auth A]ETHANOLAMINE
C2 H7 N O
HZAXFHJVJLSVMW-UHFFFAOYSA-N		 Ligand Interaction
CL
Query on CL
Download Ideal Coordinates CCD File 
D [auth A]CHLORIDE ION
Cl
VEXZGXHMUGYJMC-UHFFFAOYSA-M		 Ligand Interaction
Binding Affinity Annotations 
IDSourceBinding Affinity
VIV BindingDB:  5MUE Kd: 2.4 (nM) from 1 assay(s)
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.40 Å
  • R-Value Free: 0.215 
  • R-Value Work: 0.182 
  • R-Value Observed: 0.184 
  • Space Group: I 4 3 2
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 168.184α = 90
b = 168.184β = 90
c = 168.184γ = 90
Software Package:
Software NamePurpose
XSCALEdata scaling
PHASERphasing
PHENIXrefinement
PDB_EXTRACTdata extraction
XDSdata reduction

Structure Validation

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Ligand Structure Quality Assessment 


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Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2017-07-19
    Type: Initial release
  • Version 1.1: 2018-12-05
    Changes: Data collection, Source and taxonomy, Structure summary