Cross-Validation of Lipid Structure Assignment Using Orthogonal Ion Activation Modalities on the Same Mass
Samuel C Brydon1, Berwyck L J Poad1,2, Mengxuan Fang3
1School of Chemistry and Physics, Queensland University of Technology, Brisbane, QLD 4001, Australia.
Journal of the American Society for Mass Spectrometry
|July 22, 2024
Summary
New mass spectrometry methods, ozone-induced dissociation (OzID) and ultraviolet photodissociation (UVPD), accurately map double bond positions in cancer cell membrane lipids. This advances lipidomics for understanding cancer progression.
Area of Science:
- Lipidomics and Mass Spectrometry
- Cancer Biology and Molecular Mechanisms
Background:
- Cancer progression involves alterations in cellular lipidome composition.
- Accurate structural characterization of lipids is crucial for understanding cancer mechanisms.
- Determining double bond positions in membrane lipid fatty acyl chains is analytically challenging.
Purpose of the Study:
- To evaluate ozone-induced dissociation (OzID) and ultraviolet photodissociation (UVPD) for lipid structural characterization.
- To compare the performance of OzID and UVPD for identifying lipid isomers.
- To investigate fragmentation pathways of OzID and UVPD for lipid analysis.
Main Methods:
- Acquisition of OzID and UVPD mass spectra on the same mass spectrometer.
- Analysis of lipid standards to expand fragmentation rules for OzID and UVPD.
- Application of both techniques to unsaturated phosphatidylcholines from colorectal cancer cell lines.
Main Results:
- OzID and UVPD provide complementary fragmentation data for lipid identification.
- Expanded fragmentation rules enhance confidence in assigning double bond positions and resolving regioisomers.
- High confidence in assigning multiple double bond isomers in cancer cell lipids and cross-validation of abundance changes.
Conclusions:
- OzID and UVPD are powerful, complementary techniques for detailed lipid structural analysis.
- These methods enable accurate assignment of double bond positions, crucial for cancer lipidomics.
- The study provides a robust framework for investigating lipid alterations in cancer.
Related Concept Videos
01:15High-Resolution Mass Spectrometry (HRMS)
1.3K
The resolution of a mass spectrometer depends on the efficiency of separating ions with different ion masses. The mass of an atom is approximated to the sum of the masses of protons and neutrons inside, considering the masses of protons and neutrons as equal. However, the masses of the proton (1.6726 × 10−24 g) and neutron (1.6749 × 10−24 g) are not truly equal. There is a minor error in the expression of atomic masses relative to the simplest atom of hydrogen. For...
1.3K
01:33Peptide Identification Using Tandem Mass Spectrometry
6.4K
Tandem mass spectrometry, also known as MS/MS or MS2, is an analytical technique that employs two mass analyzers. Essentially it is a series of mass spectrometers that helps isolate a particular biomolecule and then helps study its chemical properties.
This technique helps gather information regarding the protein from which the peptide was obtained and to study the peptides’ amino acid sequence. Identifying peptides from a complex mixture is an important component of the growing field of...
This technique helps gather information regarding the protein from which the peptide was obtained and to study the peptides’ amino acid sequence. Identifying peptides from a complex mixture is an important component of the growing field of...
6.4K
01:19Mass Spectrometry: Overview
4.8K
Mass spectrometry is an analytical technique used to determine the molecular mass and molecular formula of a compound. The basic principle of mass spectrometry is to generate ions from the analyte molecule and measure these ion abundances against their molecular mass. One common type of ionization, known as electrospray ionization or EI, bombards the analyte molecules in the gas phase with high-energy electron beams. The electron beams displace an electron from the molecule and leave...
4.8K
01:01Mass Spectrometry: Carboxylic Acid, Ester, and Amide Fragmentation
1.2K
The fragmentation patterns observed for compounds such as carboxylic acids, esters, and amides in the mass spectra include ⍺-cleavage and McLafferty rearrangement. Fragmentation by ⍺-cleavage preferentially occurs at the carbon-carbon bond at the ⍺-position next to the carboxylic group to generate a neutral radical and a cation. Long chain compounds with hydrogen at their γ-carbon undergo McLafferty rearrangement to give a radical cation and a neutral alkene.
For example,...
For example,...
1.2K
01:21Mass Spectrometry: Complex Analysis
740
Mass spectrometry is an important technique for the identification of pure compounds. However, it has some limitations for the analysis of complex mixtures, often due to excessive fragmentation making the spectrum too complicated to decipher. Mass spectrometry can be combined with suitable separation methods in sequence, forming hyphenated methods, which are useful in the analysis of complex mixtures.
GC–MS is a powerful hyphenated method commonly used in forensics and environmental...
GC–MS is a powerful hyphenated method commonly used in forensics and environmental...
740
01:16Mass Spectrometers
5.3K
This lesson details the instrumentation of a mass spectrometer—a physical instrument to perform mass spectrometry on analyte molecules and record the characteristic mass spectra. This is achieved via three chief functions:
5.3K