Mass Spectrometry-Based Strategies for Assessing Human Exposure Using Hemoglobin Adductomics

Area of Science:

• Biomonitoring
• Analytical Chemistry
• Proteomics

Background:

• Hemoglobin (Hb) adducts are crucial biomarkers due to hemoglobin's abundance, reactivity, and adduct stability.
• Analyzing hemoglobin adducts requires robust analytical methods to understand exposure to electrophiles.

Purpose of the Study:

• To compare the efficacy of three distinct mass spectrometry-based methods for analyzing hemoglobin adducts.
• To evaluate the performance of each method in detecting adducts formed by various electrophiles.

Main Methods:

• Mass spectrometry of derivatized N-terminal Val adducts (FIRE method).
• Mass spectrometry of N-terminal adducted hemoglobin peptides (bottom-up proteomics).
• Limited proteolysis mass spectrometry.

Main Results:

• The FIRE method detected adducts from four electrophiles but struggled with others.
• Bottom-up proteomics identified adducts from all six tested electrophiles at multiple sites.
• Limited proteolysis mass spectrometry detected covalent adducts with one electrophile and metal coordination.

Conclusions:

• Each mass spectrometry approach offers complementary insights into the hemoglobin adductome.
• Bottom-up proteomics provides the most comprehensive analysis of hemoglobin adducts.
• Method selection depends on the specific electrophiles and adduct sites of interest.