1K3M

NMR STRUCTURE OF HUMAN INSULIN MUTANT ILE-A2-ALA, HIS-B10-ASP, PRO-B28-LYS, LYS-B29-PRO, 15 STRUCTURES


Experimental Data Snapshot

  • Method: SOLUTION NMR
  • Conformers Calculated: 60 
  • Conformers Submitted: 15 
  • Selection Criteria: structures with the lowest energy 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

A cavity-forming mutation in insulin induces segmental unfolding of a surrounding alpha-helix.

Xu, B.Hua, Q.X.Nakagawa, S.H.Jia, W.Chu, Y.C.Katsoyannis, P.G.Weiss, M.A.

(2002) Protein Sci. 11: 104-116

  • DOI: 10.1110/ps.32102

  • PubMed Abstract: 
  • To investigate the cooperativity of insulin's structure, a cavity-forming substitution was introduced within the hydrophobic core of an engineered monomer. The substitution, Ile(A2)-->Ala in the A1-A8 alpha-helix, does not impair disulfide pairing be ...

    To investigate the cooperativity of insulin's structure, a cavity-forming substitution was introduced within the hydrophobic core of an engineered monomer. The substitution, Ile(A2)-->Ala in the A1-A8 alpha-helix, does not impair disulfide pairing between chains. In accord with past studies of cavity-forming mutations in globular proteins, a decrement was observed in thermodynamic stability (DeltaDeltaG(u) 0.4-1.2 kcal/mole). Unexpectedly, CD studies indicate an attenuated alpha-helix content, which is assigned by NMR spectroscopy to selective destabilization of the A1-A8 segment. The analog's solution structure is otherwise similar to that of native insulin, including the B chain's supersecondary structure and a major portion of the hydrophobic core. Our results show that (1) a cavity-forming mutation in a globular protein can lead to segmental unfolding, (2) tertiary packing of Ile(A2), a residue of low helical propensity, stabilizes the A1-A8 alpha-helix, and (3) folding of this segment is not required for native disulfide pairing or overall structure. We discuss these results in relation to a hierarchical pathway of protein folding and misfolding. The Ala(A2) analog's low biological activity (0.5% relative to the parent monomer) highlights the importance of the A1-A8 alpha-helix in receptor recognition.


    Organizational Affiliation

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




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
INSULIN
A
21Homo sapiensMutation(s): 1 
Gene Names: INS
Find proteins for P01308 (Homo sapiens)
Go to Gene View: INS
Go to UniProtKB:  P01308
Entity ID: 2
MoleculeChainsSequence LengthOrganismDetails
INSULIN
B
30Homo sapiensMutation(s): 3 
Gene Names: INS
Find proteins for P01308 (Homo sapiens)
Go to Gene View: INS
Go to UniProtKB:  P01308
Experimental Data & Validation

Experimental Data

  • Method: SOLUTION NMR
  • Conformers Calculated: 60 
  • Conformers Submitted: 15 
  • Selection Criteria: structures with the lowest energy 
  • Olderado: 1K3M Olderado

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2001-10-17
    Type: Initial release
  • Version 1.1: 2008-04-27
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance