NNAS Fc mutant

Experimental Data Snapshot

  • Resolution: 2.27 Å
  • R-Value Free: 0.221 
  • R-Value Work: 0.178 
  • R-Value Observed: 0.180 

wwPDB Validation   3D Report Full Report

This is version 1.1 of the entry. See complete history


Engineered Fc-glycosylation switch to eliminate antibody effector function.

Zhou, Q.Jaworski, J.Zhou, Y.Valente, D.Cotton, J.Honey, D.Boudanova, E.Beninga, J.Rao, E.Wei, R.Mauriac, C.Pan, C.Park, A.Qiu, H.

(2020) MAbs 12: 1814583-1814583

  • DOI: https://doi.org/10.1080/19420862.2020.1814583
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 

    Antibodies mediate effector functions through Fcγ receptor (FcγR) interactions and complement activation, causing cytokine release, degranulation, phagocytosis, and cell death. They are often undesired for development of therapeutic antibodies where only antigen binding or neutralization would be ideal. Effector elimination has been successful with extensive mutagenesis, but these approaches can potentially lead to manufacturability and immunogenicity issues. By switching the native glycosylation site from position 297 to 298, we created alternative antibody glycosylation variants in the receptor interaction interface as a novel strategy to eliminate the effector functions. The engineered glycosylation site at Asn298 was confirmed by SDS-PAGE, mass spectrometry, and X-ray crystallography (PDB code 6X3I). The lead NNAS mutant (S298N/T299A/Y300S) shows no detectable binding to mouse or human FcγRs by surface plasmon resonance analyses. The effector functions of the mutant are completely eliminated when measured in antibody-dependent cell-meditated cytotoxicity (ADCC) and complement-dependent cytotoxicity (CDC) assays. In vivo , the NNAS mutant made on an antibody against a human lymphocyte antigen does not deplete T cells or B cells in transgenic mice, in contrast to wild-type antibody. Structural study confirms the successful glycosylation switch to the engineered Asn298 site. The engineered glycosylation would clash with approaching FcγRs based on reported Fc-FcγR co-crystal structures. In addition, the NNAS mutants of multiple antibodies retain binding to antigens and neonatal Fc receptor, exhibit comparable purification yields and thermal stability, and display normal circulation half-life in mice and non-human primate. Our work provides a novel approach for generating therapeutic antibodies devoid of any ADCC and CDC activities with potentially lower immunogenicity.

  • Organizational Affiliation

    Biologics Research, Sanofi , Framingham, MA, USA.

Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Immunoglobulin gamma-1 heavy chain223Homo sapiensMutation(s): 0 
Find proteins for P0DOX5 (Homo sapiens)
Explore P0DOX5 
Go to UniProtKB:  P0DOX5
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP0DOX5
Sequence Annotations
  • Reference Sequence


Entity ID: 2
MoleculeChains Length2D Diagram Glycosylation3D Interactions
Glycosylation Resources
GlyTouCan:  G42666HT
GlyCosmos:  G42666HT
GlyGen:  G42666HT
Small Molecules
Ligands 1 Unique
IDChains Name / Formula / InChI Key2D Diagram3D Interactions
Query on BMA

Download Ideal Coordinates CCD File 
C [auth A]beta-D-mannopyranose
C6 H12 O6
Experimental Data & Validation

Experimental Data

  • Resolution: 2.27 Å
  • R-Value Free: 0.221 
  • R-Value Work: 0.178 
  • R-Value Observed: 0.180 
  • Space Group: C 2 2 21
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 52.091α = 90
b = 142.504β = 90
c = 75.235γ = 90
Software Package:
Software NamePurpose
HKL-2000data reduction
HKL-2000data scaling
PDB_EXTRACTdata extraction

Structure Validation

View Full Validation Report

Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2020-09-23
    Type: Initial release
  • Version 1.1: 2023-10-18
    Changes: Data collection, Database references, Refinement description