Aza-Prilezhaev Aziridination-Enabled Multidimensional Analysis of Isomeric Lipids via High-Resolution U-Shaped...

Area of Science:

• Lipidomics
• Analytical Chemistry
• Biochemistry

Background:

• Unsaturated lipids are crucial for cellular functions but challenging to analyze comprehensively.
• Existing liquid chromatography tandem mass spectrometry (LC-MS/MS) methods struggle with labeling double bonds and differentiating lipid isomers.
• There is a need for novel orthogonal methods to improve lipidome profiling.

Purpose of the Study:

• To develop a sensitive method for analyzing unsaturated lipid isomerization.
• To overcome the limitations of current lipidome analysis techniques.
• To enable deep-profiling of lipidomics for disease marker discovery.

Main Methods:

• A metal- and additive-free aza-Prilezhaev aziridination (APA) reaction for labeling unsaturated lipids.
• Ion mobility mass spectrometry (IMS) coupled with U-shaped mobility analyzer and UMA-QTOF MS.
• Site-specific fragmentation analysis in MS/MS spectra and pseudo MS3 mode.

Main Results:

• Efficient labeling of both polar and nonpolar unsaturated lipids with N-H aziridine.
• Signal intensity enhancement up to 3 orders of magnitude, achieving nanomolar (nM) detection limits.
• Identification of double bond location and sn-position, differentiation of geometric isomers, and separation of lipid classes.
• Simplified spectra due to dominant monoaziridination products, even for lipids with multiple double bonds.

Conclusions:

• The developed APA-enabled IMS method offers a comprehensive solution for deep lipidome profiling.
• This technique significantly improves the sensitivity and specificity for analyzing unsaturated lipids and their isomers.
• The method holds promise for advancing lipid marker discovery in disease monitoring and diagnosis.