Orthogonal Comparison of Analytical Methods by Theoretical Reconstruction from Bottom-up Assay Data

Area of Science:

• Biopharmaceutical Analysis
• Analytical Chemistry
• Protein Therapeutics

Background:

• Ensuring the stability and efficacy of protein therapeutics requires robust analytical characterization.
• Mass spectrometry (MS) is a key technique for assessing chemical and structural stability.
• Comparing different MS configurations (e.g., bottom-up vs. intact) and capillary isoelectric focusing presents analytical challenges.

Purpose of the Study:

• To evaluate and compare various analytical techniques for characterizing protein therapeutic stability.
• To develop a method for reconstructing intact mass spectra and electropherograms from bottom-up data.
• To enhance the qualitative and quantitative assessment of drug candidate stability and modifications.

Main Methods:

• Utilizing bottom-up methods (e.g., peptide mapping) to quantify site-specific degradations.
• Reconstructing theoretical intact mass spectra and theoretical electropherograms from bottom-up data.
• Superimposing theoretical reconstructions over experimental intact and capillary isoelectric focusing data for comparison.

Main Results:

• Theoretical reconstructions from bottom-up data can accurately overlay experimental data when both are precise.
• This approach allows for qualitative and potentially quantitative evaluation of stability and modifications.
• Secondary information regarding stochastic modifications and combined modification effects can be obtained.

Conclusions:

• Comparing data from bottom-up and intact analyses provides a holistic view of protein therapeutics.
• Reconstruction methods aid in identifying unknown mass differences and understanding complex modification patterns.
• This integrated analytical strategy improves the comprehensive assessment of drug candidate stability.