Revealing Corynebacterium glutamicum proteoforms through top-down proteomics

Area of Science:

• Microbiology
• Proteomics
• Biotechnology

Background:

• Corynebacterium glutamicum is a key industrial microorganism for producing amino acids and other valuable compounds.
• Post-translational modifications (PTMs) are known to regulate C. glutamicum metabolism, but comprehensive proteoform characterization was lacking.

Purpose of the Study:

• To characterize C. glutamicum proteoforms and their post-translational modifications (PTMs) using a top-down proteomics approach.
• To identify novel PTMs and proteoforms impacting biotechnologically relevant processes in C. glutamicum.

Main Methods:

• Top-down mass spectrometry-based proteomics was employed for comprehensive proteoform analysis.
• Identification and characterization of mass shifts indicative of PTMs across the C. glutamicum proteome.

Main Results:

• 1125 proteoforms from 273 proteins were identified, with 60% exhibiting mass shifts suggesting PTMs.
• Detected PTMs include acetylation, oxidation, and formylation.
• Proteins involved in amino acid production, secretion, and oxidative stress showed mass shifts, including cleaved and formylated membrane proteins (mepB, SecG) and modified central metabolism proteins (OdhI).

Conclusions:

• This is the first top-down proteome analysis of C. glutamicum, providing a detailed view of its proteoforms and PTMs.
• The identified PTMs and novel proteoforms offer potential insights into regulating metabolic and biotechnological processes in this industrial bacterium.
• Further investigation of these modified proteoforms could enhance C. glutamicum's utility in industrial applications.