3G7W

Islet Amyloid Polypeptide (IAPP or Amylin) Residues 1 to 22 fused to Maltose Binding Protein


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.75 Å
  • R-Value Free: 0.194 
  • R-Value Work: 0.170 

wwPDB Validation 3D Report Full Report


This is version 1.3 of the entry. See complete history

Literature

Atomic structures of IAPP (amylin) fusions suggest a mechanism for fibrillation and the role of insulin in the process

Wiltzius, J.J.Sievers, S.A.Sawaya, M.R.Eisenberg, D.

(2009) Protein Sci. 18: 1521-1530

  • DOI: 10.1002/pro.145
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 
  • Islet Amyloid Polypeptide (IAPP or amylin) is a peptide hormone produced and stored in the beta-islet cells of the pancreas along with insulin. IAPP readily forms amyloid fibrils in vitro, and the deposition of fibrillar IAPP has been correlated with ...

    Islet Amyloid Polypeptide (IAPP or amylin) is a peptide hormone produced and stored in the beta-islet cells of the pancreas along with insulin. IAPP readily forms amyloid fibrils in vitro, and the deposition of fibrillar IAPP has been correlated with the pathology of type II diabetes. The mechanism of the conversion that IAPP undergoes from soluble to fibrillar forms has been unclear. By chaperoning IAPP through fusion to maltose binding protein, we find that IAPP can adopt a alpha-helical structure at residues 8-18 and 22-27 and that molecules of IAPP dimerize. Mutational analysis suggests that this dimerization is on the pathway to fibrillation. The structure suggests how IAPP may heterodimerize with insulin, which we confirmed by protein crosslinking. Taken together, these experiments suggest the helical dimerization of IAPP accelerates fibril formation and that insulin impedes fibrillation by blocking the IAPP dimerization interface.


    Organizational Affiliation

    Howard Hughes Medical Institute, UCLA-DOE Institute of Genomics and Proteomics, Los Angeles, California 90095-1570, USA.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Maltose-binding periplasmic protein, Islet amyloid polypeptide fusion protein
A
393Homo sapiensEscherichia coli (strain K12)
This entity is chimeric
Mutation(s): 3 
Gene Names: IAPP, malE
Find proteins for P10997 (Homo sapiens)
Go to Gene View: IAPP
Go to UniProtKB:  P10997
Find proteins for P0AEX9 (Escherichia coli (strain K12))
Go to UniProtKB:  P0AEX9
Small Molecules
Ligands 3 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
MLR
Query on MLR

Download SDF File 
Download CCD File 
A
MALTOTRIOSE
AMYLOTRIOSE
C18 H32 O16
FYGDTMLNYKFZSV-PXXRMHSHSA-N
 Ligand Interaction
SO4
Query on SO4

Download SDF File 
Download CCD File 
A
SULFATE ION
O4 S
QAOWNCQODCNURD-UHFFFAOYSA-L
 Ligand Interaction
GOL
Query on GOL

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Download CCD File 
A
GLYCEROL
GLYCERIN; PROPANE-1,2,3-TRIOL
C3 H8 O3
PEDCQBHIVMGVHV-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.75 Å
  • R-Value Free: 0.194 
  • R-Value Work: 0.170 
  • Space Group: P 41 21 2
Unit Cell:
Length (Å)Angle (°)
a = 84.495α = 90.00
b = 84.495β = 90.00
c = 144.292γ = 90.00
Software Package:
Software NamePurpose
PDB_EXTRACTdata extraction
DENZOdata reduction
PHASERphasing
BOSdata collection
REFMACrefinement
SCALEPACKdata scaling

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2009-06-23
    Type: Initial release
  • Version 1.1: 2011-07-13
    Type: Advisory, Derived calculations, Version format compliance
  • Version 1.2: 2017-08-16
    Type: Refinement description, Source and taxonomy
  • Version 1.3: 2017-11-01
    Type: Refinement description