Macromolecule Content

• Total Structure Weight: 5.75 kDa 
• Atom Count: 400 
• Modelled Residue Count: 51 
• Deposited Residue Count: 51 
• Unique protein chains: 2

1K3M

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

• DOI: 10.2210/pdb1K3M/pdb
• BMRB: 5246

• Classification: HORMONE/GROWTH FACTOR
• Mutation(s): Yes 


• Deposited: 2001-10-03 Released: 2001-10-17 
• Deposition Author(s): Xu, B., Hua, Q.-X., Nakagawa, S.H., Jia, W., Chu, Y.-C., Katsoyannis, P.G., Weiss, M.A.

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Experimental Data Snapshot

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

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

• PubMed: 11742127 
• DOI: 10.1110/ps.32102
• Primary Citation of Related Structures:  
  1K3M


• 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 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.

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Organizational Affiliation: 

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

Macromolecules

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details	Image
INSULIN	A	21	N/A	Mutation(s): 1
Find proteins for P01308 (Homo sapiens) Explore P01308  Go to UniProtKB:  P01308
NIH Common Fund Data Resources
PHAROS:  P01308

Entity ID: 2
Molecule	Chains	Sequence Length	Organism	Details	Image
INSULIN	B	30	N/A	Mutation(s): 3
Find proteins for P01308 (Homo sapiens) Explore P01308  Go to UniProtKB:  P01308
NIH Common Fund Data Resources
PHAROS:  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

Entry History 

Deposition Data

• Deposited Date: 2001-10-03 
• Released Date: 2001-10-17 
Deposition Author(s): Xu, B., Hua, Q.-X., Nakagawa, S.H., Jia, W., Chu, Y.-C., Katsoyannis, P.G., Weiss, M.A.

Revision History  

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