High-Throughput Epitope Mapping by Hydrogen Exchange-Mass Spectrometry

Area of Science:

• Biochemistry
• Immunology
• Analytical Chemistry

Background:

• Epitope mapping is crucial for understanding antigen-antibody interactions.
• Traditional hydrogen exchange mass spectrometry (HX-MS) provides detailed epitope information but is time-consuming.
• There is a need for faster epitope mapping methods in antibody development and diagnostics.

Purpose of the Study:

• To introduce and validate a high-throughput screening protocol for epitope mapping using HX-MS.
• To compare the efficiency and accuracy of the screening protocol against the traditional HX-MS method.
• To demonstrate the applicability of the screening protocol for antigen analysis.

Main Methods:

• Developed a novel HX-MS screening protocol utilizing three labeling times (20, 1000, and 86400 s) without replicates.
• Anchored the screening protocol on a single traditional HX-MS experiment (five labeling times in triplicate) to define parameters.
• Applied both protocols to map epitopes on the Borrelia burgdorferi outer surface protein A (OspA) antigen.

Main Results:

• The screening protocol identified identical epitopes on OspA compared to the traditional complete HX-MS protocol.
• The screening protocol demonstrated a 5-fold increase in throughput compared to the traditional method.
• Results were consistent with previously reported epitope mapping data for OspA.

Conclusions:

• The developed HX-MS screening protocol is a faster and efficient alternative for epitope mapping.
• This high-throughput method retains accuracy in epitope identification.
• The protocol has significant implications for accelerating antibody discovery and characterization.