5TXD

Structure of amyloid-beta derived peptide - NKGAIF


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.45 Å
  • R-Value Free: 0.191 
  • R-Value Work: 0.174 
  • R-Value Observed: 0.176 

wwPDB Validation   3D Report Full Report


This is version 1.1 of the entry. See complete history


Literature

Distal amyloid beta-protein fragments template amyloid assembly.

Do, T.D.Sangwan, S.de Almeida, N.E.C.Ilitchev, A.I.Giammona, M.Sawaya, M.R.Buratto, S.K.Eisenberg, D.S.Bowers, M.T.

(2018) Protein Sci 27: 1181-1190

  • DOI: 10.1002/pro.3375
  • Primary Citation of Related Structures:  
    5TXD, 5TXH, 5TXJ

  • PubMed Abstract: 
  • Amyloid formation is associated with devastating diseases such as Alzheimer's, Parkinson's and Type-2 diabetes. The large amyloid deposits found in patients suffering from these diseases have remained difficult to probe by structural means. Recent NMR models also predict heterotypic interactions from distinct peptide fragments but limited evidence of heterotypic packed sheets is observed in solution ...

    Amyloid formation is associated with devastating diseases such as Alzheimer's, Parkinson's and Type-2 diabetes. The large amyloid deposits found in patients suffering from these diseases have remained difficult to probe by structural means. Recent NMR models also predict heterotypic interactions from distinct peptide fragments but limited evidence of heterotypic packed sheets is observed in solution. Here we characterize two segments of the protein amyloid β (Aβ) known to form fibrils in Alzheimer's disease patients. We designed two variants of Aβ(19-24) and Aβ(27-32), IFAEDV (I6V) and NKGAIF (N6F) to lower the aggregation propensity of individual peptides while maintaining the similar interactions between the two segments in their native forms. We found that the variants do not form significant amyloid fibrils individually but a 1:1 mixture forms abundant fibrils. Using ion mobility-mass spectrometry (IM-MS), hetero-oligomers up to decamers were found in the mixture while the individual peptides formed primarily dimers and some tetramers consistent with a strong heterotypic interaction between the two segments. We showed by X-ray crystallography that I6V formed a Class 7 zipper with a weakly packed pair of β-sheets and no segregated dry interface, while N6F formed a more stable Class 1 zipper. In a mixture of equimolar N6F:I6V, I6V forms a more stable zipper than in I6V alone while no N6F or hetero-typic zippers are observed. These data are consistent with a mechanism where N6F catalyzes assembly of I6V into a stable zipper and perhaps into stable, pure I6V fibrils that are observed in AFM measurements.


    Organizational Affiliation

    Department of Chemistry and Biochemistry, University of California, Santa Barbara, California.



Macromolecules

Find similar proteins by:  Sequence   |   3D Structure  

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
Amyloid beta A4 proteinA [auth Z]6Homo sapiensMutation(s): 0 
Gene Names: APPA4AD1
UniProt & NIH Common Fund Data Resources
Find proteins for P05067 (Homo sapiens)
Explore P05067 
Go to UniProtKB:  P05067
PHAROS:  P05067
Entity Groups  
UniProt GroupP05067
Protein Feature View
Expand
  • Reference Sequence
Small Molecules
Ligands 1 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
PO4
Query on PO4

Download Ideal Coordinates CCD File 
B [auth Z]PHOSPHATE ION
O4 P
NBIIXXVUZAFLBC-UHFFFAOYSA-K
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.45 Å
  • R-Value Free: 0.191 
  • R-Value Work: 0.174 
  • R-Value Observed: 0.176 
  • Space Group: C 1 2 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 29.402α = 90
b = 4.827β = 102.04
c = 26.612γ = 90
Software Package:
Software NamePurpose
REFMACrefinement
PDB_EXTRACTdata extraction
PHENIXrefinement
XDSdata reduction
XSCALEdata scaling
PHASERphasing

Structure Validation

View Full Validation Report



Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2017-11-15
    Type: Initial release
  • Version 1.1: 2018-10-10
    Changes: Data collection, Database references, Structure summary