1.8 Angstrom crystal structure of IGF-1

Experimental Data Snapshot

  • Resolution: 1.82 Å
  • R-Value Free: 0.258 
  • R-Value Work: 0.245 

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This is version 1.2 of the entry. See complete history


Crystal structure of human insulin-like growth factor-1: detergent binding inhibits binding protein interactions.

Vajdos, F.F.Ultsch, M.Schaffer, M.L.Deshayes, K.D.Liu, J.Skelton, N.J.de Vos, A.M.

(2001) Biochemistry 40: 11022-11029

  • DOI: https://doi.org/10.1021/bi0109111
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 

    Despite efforts spanning considerably more than a decade, a high-resolution view of the family of proteins known as insulin-like growth factors (IGFs) has remained elusive. IGF-1 consists of three helical segments which are connected by a 12-residue linker known as the C-region. NMR studies of members of this family reveal a dynamic structure with a topology resembling insulin but little structural definition in the C-region. We have crystallized IGF-1 in the presence of the detergent deoxy big CHAPS, and determined its structure at 1.8 A resolution by multiwavelength anomalous diffraction, exploiting the anomalous scattering of a single bromide ion and six of the seven sulfur atoms of IGF-1. The structure reveals a well-defined conformation for much of the C-region, which extends away from the core of IGF-1 and has residues known to be involved in receptor binding prominently displayed in a type II beta-turn. In the crystal, these residues form a dimer interface, but analytical ultracentrifugation experiments demonstrate that at physiological concentrations IGF-1 is monomeric. A single detergent molecule contacts residues known to be important for IGF-1 binding protein (IGFBP) interactions. Biophysical and biochemical data show that the detergent binds to IGF-1 specifically and blocks binding of IGFBP-1 and IGFBP-3.

  • Organizational Affiliation

    Department of Protein Engineering, Genentech, Inc., 1 DNA Way, South San Francisco, California 94080, USA.

Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Insulin-like Growth Factor 1A70Homo sapiensMutation(s): 0 
Gene Names: IGF-1
UniProt & NIH Common Fund Data Resources
Find proteins for P05019 (Homo sapiens)
Explore P05019 
Go to UniProtKB:  P05019
GTEx:  ENSG00000017427 
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP05019
Sequence Annotations
  • Reference Sequence
Small Molecules
Ligands 2 Unique
IDChains Name / Formula / InChI Key2D Diagram3D Interactions
Query on CPQ

Download Ideal Coordinates CCD File 
C42 H75 N3 O15
Query on BR

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Binding Affinity Annotations 
IDSourceBinding Affinity
CPQ PDBBind:  1IMX Kd: 3.00e+5 (nM) from 1 assay(s)
Experimental Data & Validation

Experimental Data

  • Resolution: 1.82 Å
  • R-Value Free: 0.258 
  • R-Value Work: 0.245 
  • Space Group: C 2 2 21
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 31.831α = 90
b = 71.055β = 90
c = 65.996γ = 90
Software Package:
Software NamePurpose
DENZOdata reduction
SCALEPACKdata scaling

Structure Validation

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Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2001-09-05
    Type: Initial release
  • Version 1.1: 2008-04-27
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Version format compliance