Disulfide linkage assignment based on reducing electrochemistry and mass spectrometry using a lead electrode

Area of Science:

• Biochemistry and Analytical Chemistry
• Mass Spectrometry Applications
• Biopharmaceutical Quality Control

Background:

• Disulfide bonds are critical for protein structure, stability, and function.
• Accurate disulfide linkage assignment is essential for biopharmaceutical product quality assessment.
• Existing methods struggle with complex disulfide bonds, especially nested ones.

Purpose of the Study:

• To develop a novel, efficient method for disulfide linkage assignment in disulfide-rich peptides and proteins.
• To address the challenge of analyzing nested disulfide bonds formed by closely spaced cysteine residues.
• To provide a rapid and robust analytical tool for biopharmaceutical characterization.

Main Methods:

• Utilized electrochemical reduction on a lead electrode for disulfide bond cleavage.
• Employed partial electrochemical reduction followed by alkylation of peptides.
• Analyzed alkylated peptides using tandem mass spectrometry for sequencing and linkage assignment.

Main Results:

• Successfully demonstrated a novel approach for disulfide linkage assignment.
• The method effectively cleaved disulfide bonds in peptides and proteins with nested structures.
• Lead electrode proved advantageous due to ease of use, reusability, and minimal maintenance.

Conclusions:

• The presented electrochemical reduction method offers a rapid and effective solution for disulfide linkage analysis.
• This technique is particularly valuable for complex peptides and proteins, including those with nested disulfide bonds.
• The method simplifies sample preparation and avoids chemical reducing agents, enhancing its applicability in biopharmaceutical analysis.