Related Experiment Video
Updated: Aug 14, 2026
12:07
Chemical Modification of the Tryptophan Residue in a Recombinant Ca2+-ATPase N-domain for Studying Tryptophan-ANS FRET
Published on: October 9, 2021
Local electrostatics governs tryptophan oxidation and enables rational stability engineering in antibodies
Sunidhi Lenka1, Shrenik Mehta1, Nicole Stephens2
1Pharmaceutical Development, Genentech, South San Francisco, CA, USA.
Mabs
|August 13, 2026
Summary
Oxidation of tryptophan residues in therapeutic antibodies is a stability concern. Local electrostatics, alongside solvent accessibility, significantly predicts and can be engineered to reduce oxidation risk in antibody complementarity-determining regions (CDRs).
Area of Science:
- Biochemistry
- Protein Engineering
- Computational Biology
Background:
- Oxidation of tryptophan (Trp) residues in therapeutic antibody complementarity-determining regions (CDRs) compromises antibody efficacy and stability.
- Understanding the molecular basis of site-specific Trp oxidation susceptibility is crucial for antibody developability.
Purpose of the Study:
- To develop a predictive model for Trp oxidation risk in therapeutic antibodies.
- To identify key physicochemical drivers of Trp oxidation beyond solvent accessibility.
- To engineer antibodies with reduced oxidation susceptibility while preserving binding affinity.
Main Methods:
- A structure-informed machine learning framework was developed using Trp oxidation data from 187 monoclonal antibodies.
- Local residue-level electrostatic potential (Epot) was identified as a significant predictor of oxidation risk.
- Distal charge-altering mutations and redox replica-exchange molecular dynamics simulations were employed for antibody engineering and mechanistic studies.
Main Results:
- A two-parameter model (solvent accessibility and Epot) achieved 79% classification accuracy for Trp oxidation risk.
- Local negative Epot was found to markedly increase oxidation susceptibility.
- Distal charge-altering mutations reduced oxidation rates by approximately 50% in engineered antibodies, with preserved binding affinity in some cases.
- A clinically relevant antibody variant showed up to 50% oxidation reduction with minimal affinity loss.
Conclusions:
- Local residue-level electrostatics is a critical, tunable determinant of Trp oxidation susceptibility in therapeutic antibodies.
- Electrostatic engineering offers a rational approach to enhance antibody oxidation stability without compromising antigen-binding function.
- The developed framework provides a practical tool for optimizing antibody developability.
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