1PZ5

Structural basis of peptide-carbohydrate mimicry in an antibody combining site


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.80 Å
  • R-Value Free: 0.254 
  • R-Value Work: 0.219 
  • R-Value Observed: 0.219 

wwPDB Validation   3D Report Full Report


This is version 1.3 of the entry. See complete history


Literature

Structural basis of peptide-carbohydrate mimicry in an antibody combining site.

Vyas, N.K.Vyas, M.N.Chervenak, M.C.Bundle, D.R.Pinto, B.M.Quiocho, F.A.

(2003) Proc Natl Acad Sci U S A 100: 15023-15028

  • DOI: 10.1073/pnas.2431286100
  • Primary Citation of Related Structures:  
    1PZ5

  • PubMed Abstract: 
  • The structure of a complex between the Fab fragment of the antibody (SYA/J6) specific for the cell surface O-antigen polysaccharide of the pathogen Shigella flexneri Y and an octapeptide (Met-Asp-Trp-Asn-Met-His-Ala-Ala), a functional mimic of the O- ...

    The structure of a complex between the Fab fragment of the antibody (SYA/J6) specific for the cell surface O-antigen polysaccharide of the pathogen Shigella flexneri Y and an octapeptide (Met-Asp-Trp-Asn-Met-His-Ala-Ala), a functional mimic of the O-antigen, has been determined at 1.8-A resolution. Comparison of the structure with that of the complex with the pentasaccharide antigen [-->2)-alpha-L-Rha-(1-->2)-alpha-L-Rha-(1-->3)-alpha-L-Rha-(1-->3)-beta-D-GlcNAc-(1-->2)-alpha-L-Rha-(1-->] reveals the molecular recognition process by which a peptide mimics a carbohydrate in binding to an antibody. The binding modes of the two ligands differ considerably. Octapeptide binding complements the shape of the combining site groove much better than pentasaccharide binding. Moreover, the peptide makes a much greater number of contacts (126), which are mostly van der Waals interactions, with the Fab than the saccharide (74). An unusual feature is also the involvement of 12 water molecules in mediating hydrogen bonds between residues within the peptide or of the peptide and Fab. Despite better shape complementarity and greater number of contacts, the octapeptide binds with an affinity (KA = 2.5 x 10(5) M-1, measured by calorimetry) only approximately 2-fold tighter than the pentasaccharide. The structural results are relevant to the design of peptide mimetics with improved affinity for use as vaccines.


    Related Citations: 
    • Molecular recognition of oligosaccharide epitopes by a monoclonal Fab sepcific for Shigella flexneri Y lipopolysaccharide: X-ray structures and thermodynamics.
      Vyas, N.K., Vyas, M.N., Chervenak, M.C., Johnson, M.A., Pinto, B.M., Bundle, D.R., Quiocho, F.A.
      (2002) Biochemistry 41: 13575
    • Preliminary crystallographic analysis of a Fab specific for the O-antigen of Shigella flexneri cell surface lipopoysaccharide with and without bound saccharides
      Vyas, M.N., Vyas, N.K., Meikle, P.J., Sinnott, B., Pinto, B.M., Bundle, D.R., Quiocho, F.A.
      (1993) J Mol Biol 231: 133

    Organizational Affiliation

    Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX 77030, USA.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
Light chain of Fab (SYA/J6)A215Mus musculusMutation(s): 0 
Gene Names: IgkcIgk-C
Find proteins for A2NHM3 (Mus musculus)
Explore A2NHM3 
Go to UniProtKB:  A2NHM3
Protein Feature View
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  • Reference Sequence
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Entity ID: 2
MoleculeChainsSequence LengthOrganismDetailsImage
Heavy chain of Fab (SYA/J6)B220Mus musculusMutation(s): 0 
Find proteins for P01801 (Mus musculus)
Explore P01801 
Go to UniProtKB:  P01801
Protein Feature View
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  • Reference Sequence
  • Find similar proteins by:  Sequence   |   Structure
Entity ID: 3
MoleculeChainsSequence LengthOrganismDetailsImage
Octapeptide (MDWNMHAA)C8N/AMutation(s): 0 
Protein Feature View
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  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.80 Å
  • R-Value Free: 0.254 
  • R-Value Work: 0.219 
  • R-Value Observed: 0.219 
  • Space Group: P 43 21 2
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 69.31α = 90
b = 69.31β = 90
c = 198.56γ = 90
Software Package:
Software NamePurpose
CNSrefinement
DENZOdata reduction
SCALEPACKdata scaling
CNSphasing

Structure Validation

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Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2003-11-18
    Type: Initial release
  • Version 1.1: 2008-04-29
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Version format compliance
  • Version 1.3: 2011-11-16
    Changes: Atomic model