1XFP

Crystal structure of the CDR2 germline reversion mutant of cAb-Lys3 in complex with hen egg white lysozyme


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.50 Å
  • R-Value Free: 0.216 
  • R-Value Work: 0.201 
  • R-Value Observed: 0.201 

wwPDB Validation   3D Report Full Report


This is version 1.3 of the entry. See complete history


Literature

Chemical Basis for the Affinity Maturation of a Camel Single Domain Antibody

De Genst, E.Handelberg, F.Van Meirhaeghe, A.Vynck, S.Loris, R.Wyns, L.Muyldermans, S.

(2004) J Biol Chem 279: 53593-53601

  • DOI: 10.1074/jbc.M407843200
  • Primary Citation of Related Structures:  
    1XFP

  • PubMed Abstract: 
  • Affinity maturation of classic antibodies supposedly proceeds through the pre-organization of the reactive germ line conformational isomer. It is less evident to foresee how this can be accomplished by camelid heavy-chain antibodies lacking light cha ...

    Affinity maturation of classic antibodies supposedly proceeds through the pre-organization of the reactive germ line conformational isomer. It is less evident to foresee how this can be accomplished by camelid heavy-chain antibodies lacking light chains. Although these antibodies are subjected to somatic hypermutation, their antigen-binding fragment consists of a single domain with restricted flexibility in favor of binding energy. An antigen-binding domain derived from a dromedary heavy-chain antibody, cAb-Lys3, accumulated five amino acid substitutions in CDR1 and CDR2 upon maturation against lysozyme. Three of these residues have hydrophobic side chains, replacing serines, and participate in the hydrophobic core of the CDR1 in the mature antibody, suggesting that conformational rearrangements might occur in this loop during maturation. However, transition state analysis of the binding kinetics of mature cAb-Lys3 and germ line variants show that the maturation of this antibody relies on events late in the reaction pathway. This is reflected by a limited perturbation of k(a) and a significantly decreased k(d) upon maturation. In addition, binding reactions and the maturation event are predominantly enthalpically driven. Therefore, maturation proceeds through the increase of favorable binding interactions, or by the reduction of the enthalpic penalty for desolvation, as opposed to large entropic penalties associated with conformational changes and structural plasticity. Furthermore, the crystal structure of the mutant with a restored germ line CDR2 sequence illustrates that the matured hydrophobic core of CDR1 in cAb-Lys3 might be compensated in the germ line precursor by burying solvent molecules engaged in a stable hydrogen-bonding network with CDR1 and CDR2.


    Organizational Affiliation

    Department of Molecular and Cellular Interactions, Vlaams Interuniversitair Instituut voor Biotechnologie, Vrije Universiteit Brussel, Pleinlaan 2, B-1050 Brussels, Belgium. edegenst@vub.ac.be



Macromolecules
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Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
heavy chain antibodyA142Camelus dromedariusMutation(s): 0 
Protein Feature View
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  • Reference Sequence
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 2
MoleculeChainsSequence LengthOrganismDetailsImage
Lysozyme CL129Gallus gallusMutation(s): 0 
Gene Names: LYZ
EC: 3.2.1.17
Find proteins for P00698 (Gallus gallus)
Explore P00698 
Go to UniProtKB:  P00698
Protein Feature View
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  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.50 Å
  • R-Value Free: 0.216 
  • R-Value Work: 0.201 
  • R-Value Observed: 0.201 
  • Space Group: C 1 2 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 128.294α = 90
b = 72.334β = 106.74
c = 38.766γ = 90
Software Package:
Software NamePurpose
CNSrefinement
DENZOdata reduction
CCP4data scaling
AMoREphasing

Structure Validation

View Full Validation Report



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2004-09-28
    Type: Initial release
  • Version 1.1: 2008-04-30
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Version format compliance
  • Version 1.3: 2013-02-06
    Changes: Derived calculations