3LRI

Solution structure and backbone dynamics of long-[Arg(3)]insulin-like growth factor-I


Experimental Data Snapshot

  • Method: SOLUTION NMR
  • Conformers Calculated: 100 
  • Conformers Submitted: 15 
  • Selection Criteria: LOWEST ENERGY 

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This is version 1.3 of the entry. See complete history

Literature

Solution structure and backbone dynamics of long-[Arg(3)]insulin-like growth factor-I

Laajoki, L.G.Francis, G.L.Wallace, J.C.Carver, J.A.Keniry, M.A.

(2000) J.Biol.Chem. 275: 10009-10015


  • PubMed Abstract: 
  • Long-[Arg(3)]insulin-like growth factor-I (IGF-I) is a potent analog of insulin-like growth factor-I that has been modified by a Glu(3) --> Arg mutation and a 13-amino acid extension appended to the N terminus. We have determined the solution structu ...

    Long-[Arg(3)]insulin-like growth factor-I (IGF-I) is a potent analog of insulin-like growth factor-I that has been modified by a Glu(3) --> Arg mutation and a 13-amino acid extension appended to the N terminus. We have determined the solution structure of (15)N-labeled Long-[Arg(3)]-IGF-I using high resolution NMR and restrained molecular dynamics techniques to a precision of 0.82 +/- 0.28 A root mean square deviation for the backbone heavy atoms in the three alpha-helices and 3.5 +/- 0.9 A root mean square deviation for all backbone heavy atoms excluding the 8 N-terminal residues and the 8 C-terminal eight residues. Overall, the structure of the IGF-I domain is consistent with earlier studies of IGF-I with some minor changes remote from the N terminus. The major variations in the structure, compared with IGF-I, occur at the N terminus with a substantial reorientation of the N-terminal three residues of the IGF-I domain. These results are interpreted in terms of the lower binding affinity for insulin-like growth factor-binding proteins. The backbone dynamics of Long-[Arg(3)]IGF-I were investigated using (15)N nuclear spin relaxation and the heteronuclear nuclear Overhauser enhancement (NOE). There is a considerable degree of flexibility in Long-[Arg(3)]IGF-I, even in the alpha-helices, as indicated by an average ((1)H)(15)N NOE of 0.55 for the regions. The largest heteronuclear NOEs are observed in the helical regions, lower heteronuclear NOEs are observed in the C-domain loop separating helix 1 from helix 2, and negative heteronuclear NOEs are observed in the N-terminal extension and at the C terminus. Despite these data indicating conformational flexibility for the N-terminal extension, slow amide proton exchange was observed for some residues in this region, suggesting some transitory structure does exist, possibly a molten helix. A certain degree of flexibility may be necessary in all insulin-like growth factors to enable association with various receptors and binding proteins.


    Organizational Affiliation

    Research School of Chemistry, The Australian National University, Canberra, Australian Capital Territory 2601, South Australia 5000.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
PROTEIN (INSULIN-LIKE GROWTH FACTOR I)
A
83Homo sapiensMutation(s): 2 
Gene Names: IGF1 (IBP1)
Find proteins for P05019 (Homo sapiens)
Go to Gene View: IGF1
Go to UniProtKB:  P05019
Experimental Data & Validation

Experimental Data

  • Method: SOLUTION NMR
  • Conformers Calculated: 100 
  • Conformers Submitted: 15 
  • Selection Criteria: LOWEST ENERGY 
  • Olderado: 3LRI Olderado

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2000-05-23
    Type: Initial release
  • Version 1.1: 2007-10-16
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance
  • Version 1.3: 2017-11-29
    Type: Derived calculations