7RDM

Crystal structure of PCDN-38B, a broadly neutralizing anti-HIV antibody

Summary for 7RDM

• Entry DOI: 10.2210/pdb7rdm/pdb
• Related: 7RDJ 7RDK 7RDL
• Descriptor: PCDN-38B Fab light chain, PCDN-38B Fab heavy chain, alpha-D-mannopyranose-(1-6)-beta-D-mannopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose-(1-4)-[alpha-L-fucopyranose-(1-6)]2-acetamido-2-deoxy-beta-D-glucopyranose, ... (8 entities in total)
• Functional Keywords: antibody, broadly neutralizing, hiv-1, cysteinylation, immune system
• Biological source: Homo sapiens (Human); More
• Total number of polymer chains: 2
• Total formula weight: 50993.19

Authors

Omorodion, O.,Wilson, I.A. (deposition date: 2021-07-09, release date: 2021-11-10, Last modification date: 2024-10-23)

Primary citation

Omorodion, O.,Wilson, I.A.
Structural and Biochemical Characterization of Cysteinylation in Broadly Neutralizing Antibodies to HIV-1.
J.Mol.Biol., 433:167303-167303, 2021

PubMed Abstract: Antibodies with exceptional breadth and potency have been elicited in some individuals during natural HIV-1 infection. Elicitation and affinity maturation of broadly neutralizing antibodies (bnAbs) is therefore the central goal of HIV-1 vaccine development. The functional properties of bnAbs also make them attractive as immunotherapeutic agents, which has led to their production and optimization for passive immunotherapy. This process requires in vitro manufacturing and monitoring of any heterogeneous expression, especially when subpopulations of antibodies are produced with varying levels of biological activity. Post-translational modification (PTM) of antibodies can contribute to heterogeneity and is the focus of this study. Specifically, we have investigated cysteinylation in a bnAb lineage (PCDN family) targeting the N332-glycan supersite on the surface envelope glycoprotein (Env) of HIV-1. This PTM is defined by capping of unpaired cysteine residues with molecular cysteine. Through chromatography and mass spectrometry, we were able to characterize subpopulations of cysteinylated and non-cysteinylated antibodies when expressed in mammalian cells. The crystal structures of two PCDN antibodies represent the first structures of a cysteinylated antibody and reveal that the cysteinylation in this case is located in CDRH3. Biophysical studies indicate that cysteinylation of these HIV-1 antibodies does not interfere with antigen binding, which has been reported to occur in other cysteinylated antibodies. As such, these studies highlight the need for further investigation of cysteinylation in anti-HIV and other bnAbs.

PubMed: 34666044
DOI: 10.1016/j.jmb.2021.167303

Experimental method

X-RAY DIFFRACTION (2.08 Å)