3TNM

Crystal structure of A32 Fab, an ADCC mediating anti-HIV-1 antibody


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.85 Å
  • R-Value Free: 0.232 
  • R-Value Work: 0.187 

wwPDB Validation 3D Report Full Report


This is version 1.1 of the entry. See complete history

Literature

Diverse specificity and effector function among human antibodies to HIV-1 envelope glycoprotein epitopes exposed by CD4 binding.

Guan, Y.Pazgier, M.Sajadi, M.M.Kamin-Lewis, R.Al-Darmarki, S.Flinko, R.Lovo, E.Wu, X.Robinson, J.E.Seaman, M.S.Fouts, T.R.Gallo, R.C.DeVico, A.L.Lewis, G.K.

(2013) Proc.Natl.Acad.Sci.USA 110: E69-E78

  • DOI: 10.1073/pnas.1217609110

  • PubMed Abstract: 
  • The HIV-1 envelope glycoprotein (Env) undergoes conformational transitions consequent to CD4 binding and coreceptor engagement during viral entry. The physical steps in this process are becoming defined, but less is known about their significance as ...

    The HIV-1 envelope glycoprotein (Env) undergoes conformational transitions consequent to CD4 binding and coreceptor engagement during viral entry. The physical steps in this process are becoming defined, but less is known about their significance as targets of antibodies potentially protective against HIV-1 infection. Here we probe the functional significance of transitional epitope exposure by characterizing 41 human mAbs specific for epitopes exposed on trimeric Env after CD4 engagement. These mAbs recognize three epitope clusters: cluster A, the gp120 face occluded by gp41 in trimeric Env; cluster B, a region proximal to the coreceptor-binding site (CoRBS) and involving the V1/V2 domain; and cluster C, the coreceptor-binding site. The mAbs were evaluated functionally by antibody-dependent, cell-mediated cytotoxicity (ADCC) and for neutralization of Tiers 1 and 2 pseudoviruses. All three clusters included mAbs mediating ADCC. However, there was a strong potency bias for cluster A, which harbors at least three potent ADCC epitopes whose cognate mAbs have electropositive paratopes. Cluster A epitopes are functional ADCC targets during viral entry in an assay format using virion-sensitized target cells. In contrast, only cluster C contained epitopes that were recognized by neutralizing mAbs. There was significant diversity in breadth and potency that correlated with epitope fine specificity. In contrast, ADCC potency had no relationship with neutralization potency or breadth for any epitope cluster. Thus, Fc-mediated effector function and neutralization coselect with specificity in anti-Env antibody responses, but the nature of selection is distinct for these two antiviral activities.


    Organizational Affiliation

    Division of Basic Science and Vaccine Research, Institute of Human Virology, University of Maryland School of Medicine, Baltimore, MD 21201, USA.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Fab heavy chain of human anti-HIV-1 Env antibody A32
H, A
231N/AN/A
Protein Feature View is not available: No corresponding UniProt sequence found.
Entity ID: 2
MoleculeChainsSequence LengthOrganismDetails
Fab light chain of human anti-HIV-1 Env antibody A32
L, B
216N/AN/A
Protein Feature View is not available: No corresponding UniProt sequence found.
Small Molecules
Ligands 2 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
ACT
Query on ACT

Download SDF File 
Download CCD File 
L
ACETATE ION
C2 H3 O2
QTBSBXVTEAMEQO-UHFFFAOYSA-M
 Ligand Interaction
CL
Query on CL

Download SDF File 
Download CCD File 
A, L
CHLORIDE ION
Cl
VEXZGXHMUGYJMC-UHFFFAOYSA-M
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.85 Å
  • R-Value Free: 0.232 
  • R-Value Work: 0.187 
  • Space Group: P 1
Unit Cell:
Length (Å)Angle (°)
a = 40.780α = 103.69
b = 71.316β = 104.02
c = 77.673γ = 105.40
Software Package:
Software NamePurpose
DENZOdata reduction
HKL-2000data collection
SCALEPACKdata scaling
REFMACrefinement
PHASERphasing

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

  • Deposited Date: 2011-09-01 
  • Released Date: 2012-09-26 
  • Deposition Author(s): Wu, X., Pazgier, M.

Revision History 

  • Version 1.0: 2012-09-26
    Type: Initial release
  • Version 1.1: 2015-10-14
    Type: Database references