Characterizing Antibody Cross-Links via SEC-MS Segmentation
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Solution Overview
Problem
Current methods are inadequate for characterizing high molecular weight (HMW) species of therapeutic proteins at the local residue level, particularly in understanding covalent crosslinking chemistry, which is crucial for ensuring drug safety and efficacy due to their potential to elicit immunogenic responses.
Innovation Solution
The development of advanced mass spectrometry-based techniques, including post-column denaturation-assisted native size exclusion chromatography-mass spectrometry (nSEC-MS) and denaturing size exclusion chromatography-mass spectrometry (dSEC-MS), combined with acid treatment and isotope labeling, to identify and characterize covalent cross-links in therapeutic antibodies, enabling detailed analysis of HMW species formation mechanisms.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional characterization methods are used for HMW species, then analysis can be performed at intact or subunit levels, but local residue level characterization and crosslinking chemistry understanding remain insufficient
Solution Approach 1:
The patent segments the HMW species analysis into multiple stages: intact protein analysis by nSEC-MS, enzymatic digestion into subunits, further digestion into peptides, and crosslinked peptide identification. This segmentation enables local residue level characterization while managing system complexity through hierarchical analysis
Solution Approach 2:
The patent introduces enzymatic digestion (trypsin, IdeS) as intermediary steps that break down complex HMW species into analyzable components. These enzymatic intermediaries enable the transition from intact protein analysis to peptide-level crosslink characterization without requiring direct analysis of the entire complex structure
2Loss of information
If advanced mass spectrometry techniques are implemented for local residue level characterization, then crosslinking chemistry can be understood, but analysis complexity and requirements increase
Solution Approach 1:
The patent applies preliminary enzymatic digestion with trypsin and IdeS to break down HMW species into manageable subunits and peptides before mass spectrometry analysis. This preliminary action simplifies the subsequent identification of crosslinked residues by reducing the complexity of the intact protein structure
Solution Approach 2:
The patent employs parameter changes including pH gradients during chromatography, enzymatic conditions for digestion, and mass spectrometry parameters to optimize the detection and characterization of crosslinked peptides, enabling detailed crosslinking mechanism information to be obtained
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
These methods allow for accurate identification and characterization of covalent cross-links in therapeutic antibodies, providing insights into HMW species formation and improving manufacturing, formulation, and storage processes, thereby enhancing the safety and efficacy of therapeutic proteins.
Implementation Method 1
subjecting the sample to size exclusion chromatography (SEC) to form at least one fraction including the at least one dimer
Implementation Method 2
contacting a portion of the enriched HMW sample to PNGase F to form a deglycosylated HMW sample
Implementation Method 3
subjecting the denatured SEC eluate to mass spectrometry analysis to obtain at least one mass measurement of the at least one dimer
Implementation Method 4
reduction with NaBH3CN
Implementation Method 5
characterizing the acid-lability of the covalent cross-link
Data Source
AI summary
The present invention generally pertains to methods of characterizing of a protein of interest. In particular, the present invention pertains to the use of post-column denaturation, size exclusion chromatography and mass spectrometry for detecting, identifying and characterizing crosslinking amino acid residues in a therapeutic antibody.