Top-Down Stability of Proteins from Rates of Oxidation (TD-SPROX) Approach for Measuring Proteoform-Specific Folding...

Area of Science:

• Proteomics
• Biophysics
• Molecular Biology

Background:

• Proteoforms play vital roles in biological processes and diseases.
• Discovering new proteoforms outpaces understanding their functional significance.
• Protein folding stability is closely linked to protein function.

Purpose of the Study:

• To develop a method for measuring proteoform-specific protein folding stability.
• To interface protein folding stability measurements with top-down proteomics.
• To identify functionally significant proteoforms.

Main Methods:

• Development of the top-down stability of proteins from the rates of oxidation (TD-SPROX) approach.
• Validation using model proteins with known folding behavior.
• Application to a <30 kDa protein fraction from MCF-7 cell lysate.

Main Results:

• The TD-SPROX approach was successfully developed and validated.
• Relative folding stabilities of 150 proteoforms from 83 proteins were characterized.
• The method enables proteoform-specific folding stability measurements.

Conclusions:

• TD-SPROX is a novel method for assessing proteoform folding stability.
• This technique bridges the gap between proteoform discovery and functional characterization.
• TD-SPROX has potential for identifying functionally relevant proteoforms in complex biological samples.