2VXT

Crystal structure of human IL-18 complexed to murine reference antibody 125-2H Fab


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.49 Å
  • R-Value Free: 0.196 
  • R-Value Work: 0.162 
  • R-Value Observed: 0.164 

wwPDB Validation   3D Report Full Report


This is version 1.3 of the entry. See complete history


Literature

Unusual Water-Mediated Antigenic Recognition of the Proinflammatory Cytokine Interleukin-18.

Argiriadi, M.A.Xiang, T.Wu, C.Ghayur, T.Borhani, D.W.

(2009) J Biol Chem 284: 24478

  • DOI: 10.1074/jbc.M109.023887
  • Primary Citation of Related Structures:  
    2VXT, 2VXU, 2VXV

  • PubMed Abstract: 
  • The unique cytokine interleukin-18 (IL-18) acts synergistically with IL-12 to regulate T-helper 1 and 2 lymphocytes and, as such, seems to underlie the pathogenesis of various autoimmune and allergic diseases. Several anti-IL-18 agents are in clinical development, including the recombinant human antibody ABT-325, which is entering trials for autoimmune diseases ...

    The unique cytokine interleukin-18 (IL-18) acts synergistically with IL-12 to regulate T-helper 1 and 2 lymphocytes and, as such, seems to underlie the pathogenesis of various autoimmune and allergic diseases. Several anti-IL-18 agents are in clinical development, including the recombinant human antibody ABT-325, which is entering trials for autoimmune diseases. Given competing cytokine/receptor and cytokine/receptor decoy interactions, understanding the structural basis for recognition is critical for effective development of anti-cytokine therapies. Here we report three crystal structures: the murine antibody 125-2H Fab fragment bound to human IL-18, at 1.5 A resolution; the 125-2H Fab (2.3 A); and the ABT-325 Fab (1.5 A). These structures, along with human/mouse IL-18 chimera binding data, allow us to make three key observations relevant to the biology and antigenic recognition of IL-18 and related cytokines. First, several IL-18 residues shift dramatically (> 10 A) upon binding 125-2H, compared with unbound IL-18 (Kato, Z., Jee, J., Shikano, H., Mishima, M., Ohki, I., Ohnishi, H., Li, A., Hashimoto, K., Matsukuma, E., Omoya, K., Yamamoto, Y., Yoneda, T., Hara, T., Kondo, N., and Shirakawa, M. (2003) Nat. Struct. Biol. 10, 966-971). IL-18 thus exhibits plasticity that may be common to its interactions with other receptors. Related cytokines may exhibit similar plasticity. Second, ABT-325 and 125-2H differ significantly in combining site character and architecture, thus explaining their ability to bind IL-18 simultaneously at distinct epitopes. These data allow us to define the likely ABT-325 epitope and thereby explain the distinct neutralizing mechanisms of both antibodies. Third, given the high 125-2H potency, 10 well ordered water molecules are trapped upon complex formation in a cavity between two IL-18 loops and all six 125-2H complementarity-determining regions. Thus, counterintuitively, tight and specific antibody binding may in some cases be water-mediated.


    Organizational Affiliation

    Department of Biochemistry, Abbott Laboratories, Worcester, Massachusetts 01605, USA. maria.argiriadi@abbott.com



Macromolecules
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Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
MURINE IGG 125-2HA [auth H]216Mus musculusMutation(s): 0 
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
Protein Feature View
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  • Reference Sequence
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Entity ID: 2
MoleculeChainsSequence LengthOrganismDetailsImage
INTERLEUKIN-18B [auth I]157Homo sapiensMutation(s): 4 
Gene Names: IL18IGIFIL1F4
UniProt & NIH Common Fund Data Resources
Find proteins for Q14116 (Homo sapiens)
Explore Q14116 
Go to UniProtKB:  Q14116
PHAROS:  Q14116
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupQ14116
Protein Feature View
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  • Reference Sequence
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Entity ID: 3
MoleculeChainsSequence LengthOrganismDetailsImage
MURINE IGG 125-2HC [auth L]214Mus musculusMutation(s): 0 
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
Protein Feature View
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  • Reference Sequence
Small Molecules
Ligands 2 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
CL
Query on CL

Download Ideal Coordinates CCD File 
D [auth H],
E [auth I]
CHLORIDE ION
Cl
VEXZGXHMUGYJMC-UHFFFAOYSA-M
 Ligand Interaction
MG
Query on MG

Download Ideal Coordinates CCD File 
F [auth I]MAGNESIUM ION
Mg
JLVVSXFLKOJNIY-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.49 Å
  • R-Value Free: 0.196 
  • R-Value Work: 0.162 
  • R-Value Observed: 0.164 
  • Space Group: P 1 21 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 44.345α = 90
b = 62.435β = 100.39
c = 104.734γ = 90
Software Package:
Software NamePurpose
REFMACrefinement
HKL-2000data reduction
SCALEPACKdata scaling
AMoREphasing

Structure Validation

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Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2009-06-23
    Type: Initial release
  • Version 1.1: 2011-07-13
    Changes: Advisory, Version format compliance
  • Version 1.2: 2019-03-06
    Changes: Data collection, Experimental preparation, Other
  • Version 1.3: 2019-05-08
    Changes: Data collection, Experimental preparation