1XW7

Diabetes-Associated Mutations in Human Insulin: Crystal Structure and Photo-Cross-Linking Studies of A-Chain Variant Insulin Wakayama


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.30 Å
  • R-Value Free: 0.269 
  • R-Value Work: 0.205 
  • R-Value Observed: 0.205 

wwPDB Validation   3D Report Full Report


This is version 1.5 of the entry. See complete history


Literature

Diabetes-associated mutations in human insulin: crystal structure and photo-cross-linking studies of a-chain variant insulin wakayama

Wan, Z.L.Huang, K.Xu, B.Hu, S.Q.Wang, S.Chu, Y.C.Katsoyannis, P.G.Weiss, M.A.

(2005) Biochemistry 44: 5000-5016

  • DOI: https://doi.org/10.1021/bi047585k
  • Primary Citation of Related Structures:  
    1XW7

  • PubMed Abstract: 

    Naturally occurring mutations in insulin associated with diabetes mellitus identify critical determinants of its biological activity. Here, we describe the crystal structure of insulin Wakayama, a clinical variant in which a conserved valine in the A chain (residue A3) is substituted by leucine. The substitution occurs within a crevice adjoining the classical receptor-binding surface and impairs receptor binding by 500-fold, an unusually severe decrement among mutant insulins. To resolve whether such decreased activity is directly or indirectly mediated by the variant side chain, we have determined the crystal structure of Leu(A3)-insulin and investigated the photo-cross-linking properties of an A3 analogue containing p-azidophenylalanine. The structure, characterized in a novel crystal form as an R(6) zinc hexamer at 2.3 A resolution, is essentially identical to that of the wild-type R(6) hexamer. The variant side chain remains buried in a nativelike crevice with small adjustments in surrounding side chains. The corresponding photoactivatable analogue, although of low affinity, exhibits efficient cross-linking to the insulin receptor. The site of photo-cross-linking lies within a 14 kDa C-terminal domain of the alpha-subunit. This domain, unrelated in sequence to the major insulin-binding region in the N-terminal L1 beta-helix, is also contacted by photoactivatable probes at positions A8 and B25. Packing of Val(A3) at this interface may require a conformational change in the B chain to expose the A3-related crevice. The structure of insulin Wakayama thus evokes the reasoning of Sherlock Holmes in "the curious incident of the dog in the night": the apparent absence of structural perturbations (like the dog that did not bark) provides a critical clue to the function of a hidden receptor-binding surface.


  • Organizational Affiliation

    Department of Biochemistry, School of Medicine, Case Western Reserve University, Cleveland, Ohio 44106-4935, USA.


Macromolecules

Find similar proteins by:  Sequence   |   3D Structure  

Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Insulin
A, C
21N/AMutation(s): 1 
UniProt & NIH Common Fund Data Resources
Find proteins for P01308 (Homo sapiens)
Explore P01308 
Go to UniProtKB:  P01308
PHAROS:  P01308
GTEx:  ENSG00000254647 
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP01308
Sequence Annotations
Expand
  • Reference Sequence
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 2
MoleculeChains Sequence LengthOrganismDetailsImage
Insulin
B, D
30N/AMutation(s): 0 
UniProt & NIH Common Fund Data Resources
Find proteins for P01308 (Homo sapiens)
Explore P01308 
Go to UniProtKB:  P01308
PHAROS:  P01308
GTEx:  ENSG00000254647 
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP01308
Sequence Annotations
Expand
  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.30 Å
  • R-Value Free: 0.269 
  • R-Value Work: 0.205 
  • R-Value Observed: 0.205 
  • Space Group: P 21 3
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 70.852α = 90
b = 70.852β = 90
c = 70.852γ = 90
Software Package:
Software NamePurpose
PROTEUM PLUSdata collection
PROTEUM PLUSdata reduction
CNSrefinement
PROTEUM PLUSdata scaling
CNSphasing

Structure Validation

View Full Validation Report



Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2005-04-12
    Type: Initial release
  • Version 1.1: 2008-04-30
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Derived calculations, Version format compliance
  • Version 1.3: 2017-10-11
    Changes: Refinement description
  • Version 1.4: 2021-10-20
    Changes: Database references, Derived calculations
  • Version 1.5: 2023-08-23
    Changes: Data collection, Refinement description