5BW7

Crystal structure of nonfucosylated Fc Y296W mutant complexed with bis-glycosylated soluble form of Fc gamma receptor IIIa


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 3 Å
  • R-Value Free: 0.250 
  • R-Value Work: 0.204 

wwPDB Validation 3D Report Full Report


This is version 1.1 of the entry. See complete history

Literature

Importance of the Side Chain at Position 296 of Antibody Fc in Interactions with Fc gamma RIIIa and Other Fc gamma Receptors

Isoda, Y.Yagi, H.Satoh, T.Shibata-Koyama, M.Masuda, K.Satoh, M.Kato, K.Iida, S.

(2015) Plos One 10: e0140120-e0140120

  • DOI: 10.1371/journal.pone.0140120

  • PubMed Abstract: 
  • Antibody-dependent cellular cytotoxicity (ADCC) is an important effector function determining the clinical efficacy of therapeutic antibodies. Core fucose removal from N-glycans on the Fc portion of immunoglobulin G (IgG) improves the binding affinit ...

    Antibody-dependent cellular cytotoxicity (ADCC) is an important effector function determining the clinical efficacy of therapeutic antibodies. Core fucose removal from N-glycans on the Fc portion of immunoglobulin G (IgG) improves the binding affinity for Fcγ receptor IIIa (FcγRIIIa) and dramatically enhances ADCC. Our previous structural analyses revealed that Tyr-296 of IgG1-Fc plays a critical role in the interaction with FcγRIIIa, particularly in the enhanced FcγRIIIa binding of nonfucosylated IgG1. However, the importance of the Tyr-296 residue in the antibody in the interaction with various Fcγ receptors has not yet been elucidated. To further clarify the biological importance of this residue, we established comprehensive Tyr-296 mutants as fucosylated and nonfucosylated anti-CD20 IgG1s rituximab variants and examined their binding to recombinant soluble human Fcγ receptors: shFcγRI, shFcγRIIa, shFcγRIIIa, and shFcγRIIIb. Some of the mutations affected the binding of antibody to not only shFcγRIIIa but also shFcγRIIa and shFcγRIIIb, suggesting that the Tyr-296 residue in the antibody was also involved in interactions with FcγRIIa and FcγRIIIb. For FcγRIIIa binding, almost all Tyr-296 variants showed lower binding affinities than the wild-type antibody, irrespective of their core fucosylation, particularly in Y296K and Y296P. Notably, only the Y296W mutant showed improved binding to FcγRIIIa. The 3.00 Å-resolution crystal structure of the nonfucosylated Y296W mutant in complex with shFcγRIIIa harboring two N-glycans revealed that the Tyr-to-Trp substitution increased the number of potential contact atoms in the complex, thus improving the binding of the antibody to shFcγRIIIa. The nonfucosylated Y296W mutant retained high ADCC activity, relative to the nonfucosylated wild-type IgG1, and showed greater binding affinity for FcγRIIa. Our data may improve our understanding of the biological importance of human IgG1-Fc Tyr-296 in interactions with various Fcγ receptors, and have applications in the modulation of the IgG1-Fc function of therapeutic antibodies.


    Organizational Affiliation

    Research Functions Unit, R&D Division, Kyowa Hakko Kirin Co., Ltd, Asahi-machi, Machida-shi, Tokyo, Japan.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Ig gamma-1 chain C region
A, B
223Homo sapiensMutation(s): 1 
Gene Names: IGHG1
Find proteins for P01857 (Homo sapiens)
Go to UniProtKB:  P01857
Entity ID: 2
MoleculeChainsSequence LengthOrganismDetails
Low affinity immunoglobulin gamma Fc region receptor III-A
C
179Homo sapiensMutation(s): 4 
Gene Names: FCGR3A (CD16A, FCG3, FCGR3, IGFR3)
Find proteins for P08637 (Homo sapiens)
Go to Gene View: FCGR3A
Go to UniProtKB:  P08637
Small Molecules
Ligands 6 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
CL
Query on CL

Download SDF File 
Download CCD File 
A
CHLORIDE ION
Cl
VEXZGXHMUGYJMC-UHFFFAOYSA-M
 Ligand Interaction
MAN
Query on MAN

Download SDF File 
Download CCD File 
A, B, C
ALPHA-D-MANNOSE
C6 H12 O6
WQZGKKKJIJFFOK-PQMKYFCFSA-N
 Ligand Interaction
FUC
Query on FUC

Download SDF File 
Download CCD File 
C
ALPHA-L-FUCOSE
C6 H12 O5
SHZGCJCMOBCMKK-SXUWKVJYSA-N
 Ligand Interaction
GAL
Query on GAL

Download SDF File 
Download CCD File 
A
BETA-D-GALACTOSE
C6 H12 O6
WQZGKKKJIJFFOK-FPRJBGLDSA-N
 Ligand Interaction
BMA
Query on BMA

Download SDF File 
Download CCD File 
A, B, C
BETA-D-MANNOSE
C6 H12 O6
WQZGKKKJIJFFOK-RWOPYEJCSA-N
 Ligand Interaction
NAG
Query on NAG

Download SDF File 
Download CCD File 
A, B, C
N-ACETYL-D-GLUCOSAMINE
C8 H15 N O6
OVRNDRQMDRJTHS-FMDGEEDCSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 3 Å
  • R-Value Free: 0.250 
  • R-Value Work: 0.204 
  • Space Group: P 41 21 2
Unit Cell:
Length (Å)Angle (°)
a = 77.273α = 90.00
b = 77.273β = 90.00
c = 350.983γ = 90.00
Software Package:
Software NamePurpose
MOLREPphasing
REFMACrefinement
DENZOdata reduction
SCALEPACKdata scaling

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History & Funding Information

Deposition Data


Funding OrganizationLocationGrant Number
JSPS KAKENHIJapan25102008
JSPS KAKENHIJapan24249002
National Institute of Biomedical InnovationJapan--
Okazaki ORION projectJapan--

Revision History 

  • Version 1.0: 2015-10-14
    Type: Initial release
  • Version 1.1: 2015-11-11
    Type: Database references