Let’s Chew the Fat with Orbitrap MS - Enabling Lipid Metabolic Flux Studies and Structural Elucidation of Lipids with Ultra High Resolution and UVPD Fragmentation
September 7, 2017
8:00 a.m. PDT / 11:00 a.m. EDT / 16:00 BST / 17:00 CEST
Determining lipid turnover rates (lipid metabolic flux) based on stable isotope labeling and isotope dilution analysis remains a challenging task. Deuterated water is a commonly used reagent for these experiments as it is easily incorporated into metabolic pathways and simplifies the peak assignments compared to using heavier isotopes like 18O. However, the abundance of naturally occurring 13C overlaps and often eclipses the D isotope owing to the small difference in mass defect between these isotopes, thereby complicating accurate quantitation. The first part of this webinar describes the use of ultra-high resolution MS to baseline-resolve these two peaks, greatly improving the selectivity and detection limit of this quantitative technique.
The second part of the webinar discusses the introduction of a unique fragmentation mode, ultraviolet photodissociation (UVPD) for unambiguous characterization of various lipid classes thereby representing a major breakthrough for lipid research. Locating a double bond in the acyl chain of lipid molecules used to be impossible with soft fragmentation techniques such as CID or HCD. UVPD delivers similar fragmentation behavior to that of CID or HCD, but also provides diagnostic ions indicative of double bond locations, as well as other unique structurally diagnostic information that could not be previously obtained.
TWith continued advances in mass spectrometry instrumentation, these new developments have been shown to further our understanding of lipidomics/lipid analysis that impact our understanding in health and life science research.
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• Learn about ultra-high resolution MS that allow fluxomics analysis of lipids with sensitivity comparable to radioactivity tracing.
• Learn how applying UVPD fragmentation to lipids can aid in the localization of their site(s) of unsaturation, assignment of complex backbone and headgroup identities, and the differentiation of isomeric lipids within complex mixtures.
• Researchers focused on lipidomics and metabolomics analysis.
• Researchers using stable isotope-labeling studies for pathway analysis.
• Researchers performing structure elucidation and characterization of lipid species or other small molecule endogenous metabolites.
Matt Mitsche, PhD.,
UT Southwestern Medical Center, TX
Gavin E. Reid, PhD.,
Professor of Bioanalytical Chemistry,
University of Melbourne