5J7C

A picomolar affinity FN3 domain in complex with hen egg-white lysozyme


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.54 Å
  • R-Value Free: 0.250 
  • R-Value Work: 0.218 
  • R-Value Observed: 0.219 

wwPDB Validation   3D Report Full Report


This is version 1.2 of the entry. See complete history


Literature

Circumventing the stability-function trade-off in an engineered FN3 domain.

Porebski, B.T.Conroy, P.J.Drinkwater, N.Schofield, P.Vazquez-Lombardi, R.Hunter, M.R.Hoke, D.E.Christ, D.McGowan, S.Buckle, A.M.

(2016) Protein Eng Des Sel 

  • DOI: 10.1093/protein/gzw046
  • Primary Citation of Related Structures:  
    5J7C, 5J7K

  • PubMed Abstract: 
  • The favorable biophysical attributes of non-antibody scaffolds make them attractive alternatives to monoclonal antibodies. However, due to the well-known stability-function trade-off, these gains tend to be marginal after functional selection. A notable example is the fibronectin Type III (FN3) domain, FNfn10, which has been previously evolved to bind lysozyme with 1 pM affinity (FNfn10-α-lys), but suffers from poor thermodynamic and kinetic stability ...

    The favorable biophysical attributes of non-antibody scaffolds make them attractive alternatives to monoclonal antibodies. However, due to the well-known stability-function trade-off, these gains tend to be marginal after functional selection. A notable example is the fibronectin Type III (FN3) domain, FNfn10, which has been previously evolved to bind lysozyme with 1 pM affinity (FNfn10-α-lys), but suffers from poor thermodynamic and kinetic stability. To explore this stability-function compromise further, we grafted the lysozyme-binding loops from FNfn10-α-lys onto our previously engineered, ultra-stable FN3 scaffold, FN3con. The resulting variant (FN3con-α-lys) bound lysozyme with a markedly reduced affinity, but retained high levels of thermal stability. The crystal structure of FNfn10-α-lys in complex with lysozyme revealed unanticipated interactions at the protein-protein interface involving framework residues of FNfn10-α-lys, thus explaining the failure to transfer binding via loop grafting. Utilizing this structural information, we redesigned FN3con-α-lys and restored picomolar binding affinity to lysozyme, while maintaining thermodynamic stability (with a thermal melting temperature 2-fold higher than that of FNfn10-α-lys). FN3con therefore provides an exceptional window of stability to tolerate deleterious mutations, resulting in a substantial advantage for functional design. This study emphasizes the utility of consensus design for the generation of highly stable scaffolds for downstream protein engineering studies.


    Organizational Affiliation

    Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Monash University, Clayton, VIC 3800, Australia.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
Lysozyme CA, B129Gallus gallusMutation(s): 0 
Gene Names: LYZ
EC: 3.2.1.17
UniProt
Find proteins for P00698 (Gallus gallus)
Explore P00698 
Go to UniProtKB:  P00698
Protein Feature View
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  • Reference Sequence
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 2
MoleculeChainsSequence LengthOrganismDetailsImage
FNfn10-anti-lysozyme (DE0.4.1)C, D102Homo sapiensMutation(s): 0 
Gene Names: FN1FN
UniProt & NIH Common Fund Data Resources
Find proteins for P02751 (Homo sapiens)
Explore P02751 
Go to UniProtKB:  P02751
PHAROS:  P02751
Protein Feature View
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  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.54 Å
  • R-Value Free: 0.250 
  • R-Value Work: 0.218 
  • R-Value Observed: 0.219 
  • Space Group: P 21 21 21
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 54.858α = 90
b = 87.725β = 90
c = 100.895γ = 90
Software Package:
Software NamePurpose
PHENIXrefinement
iMOSFLMdata reduction
Aimlessdata scaling
PHASERphasing

Structure Validation

View Full Validation Report




Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2016-08-17
    Type: Initial release
  • Version 1.1: 2016-09-14
    Changes: Database references
  • Version 1.2: 2016-09-21
    Changes: Database references