4M4L

The structure of Cu T6 bovine insulin


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.45 Å
  • R-Value Free: 0.204 
  • R-Value Work: 0.169 
  • R-Value Observed: 0.170 

wwPDB Validation   3D Report Full Report


This is version 1.3 of the entry. See complete history


Literature

Towards accurate structural characterization of metal centres in protein crystals: the structures of Ni and Cu T6 bovine insulin derivatives.

Frankaer, C.G.Mossin, S.Stahl, K.Harris, P.

(2014) Acta Crystallogr D Biol Crystallogr 70: 110-122

  • DOI: https://doi.org/10.1107/S1399004713029040
  • Primary Citation of Related Structures:  
    4M4F, 4M4H, 4M4I, 4M4J, 4M4L, 4M4M

  • PubMed Abstract: 

    Using synchrotron radiation (SR), the crystal structures of T6 bovine insulin complexed with Ni(2+) and Cu(2+) were solved to 1.50 and 1.45 Å resolution, respectively. The level of detail around the metal centres in these structures was highly limited, and the coordination of water in Cu site II of the copper insulin derivative was deteriorated as a consequence of radiation damage. To provide more detail, X-ray absorption spectroscopy (XAS) was used to improve the information level about metal coordination in each derivative. The nickel derivative contains hexacoordinated Ni(2+) with trigonal symmetry, whereas the copper derivative contains tetragonally distorted hexacoordinated Cu(2+) as a result of the Jahn-Teller effect, with a significantly longer coordination distance for one of the three water molecules in the coordination sphere. That the copper centre is of type II was further confirmed by electron paramagnetic resonance (EPR). The coordination distances were refined from EXAFS with standard deviations within 0.01 Å. The insulin derivative containing Cu(2+) is sensitive towards photoreduction when exposed to SR. During the reduction of Cu(2+) to Cu(+), the coordination geometry of copper changes towards lower coordination numbers. Primary damage, i.e. photoreduction, was followed directly by XANES as a function of radiation dose, while secondary damage in the form of structural changes around the Cu atoms after exposure to different radiation doses was studied by crystallography using a laboratory diffractometer. Protection against photoreduction and subsequent radiation damage was carried out by solid embedment of Cu insulin in a saccharose matrix. At 100 K the photoreduction was suppressed by ∼15%, and it was suppressed by a further ∼30% on cooling the samples to 20 K.


  • Organizational Affiliation

    Department of Chemistry, Technical University of Denmark, Kemitorvet 207, DK-2800 Kgs. Lyngby, Denmark.


Macromolecules

Find similar proteins by:  Sequence   |   3D Structure  

Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Insulin
A, C
21Bos taurusMutation(s): 0 
UniProt
Find proteins for P01317 (Bos taurus)
Explore P01317 
Go to UniProtKB:  P01317
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP01317
Sequence Annotations
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  • Reference Sequence
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 2
MoleculeChains Sequence LengthOrganismDetailsImage
Insulin
B, D
30Bos taurusMutation(s): 0 
UniProt
Find proteins for P01317 (Bos taurus)
Explore P01317 
Go to UniProtKB:  P01317
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP01317
Sequence Annotations
Expand
  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.45 Å
  • R-Value Free: 0.204 
  • R-Value Work: 0.169 
  • R-Value Observed: 0.170 
  • Space Group: H 3
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 81.36α = 90
b = 81.36β = 90
c = 33.4γ = 120
Software Package:
Software NamePurpose
MAR345dtbdata collection
MOLREPphasing
PHENIXrefinement
XDSdata reduction
XSCALEdata scaling

Structure Validation

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Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2014-01-15
    Type: Initial release
  • Version 1.1: 2014-02-12
    Changes: Database references
  • Version 1.2: 2018-03-07
    Changes: Data collection
  • Version 1.3: 2024-10-16
    Changes: Data collection, Database references, Derived calculations, Structure summary