Spatial lipid composition, distribution and regulation are very important factors for mediating lipid functionality and, when disrupted, can cause pathophysiological processes leading to cancer, obesity, atherosclerosis, and neurodegeneration. The novel LESAPLUS surface analysis approach combines the standard liquid extraction surface analysis with an additional step of a nano liquid chromatography separation. This combination is ideally suited to investigate small molecule drugs, metabolites or lipids from thin tissue sections.
Rapid Detection of Peptide Markers for Authentication Purposes in Raw and Cooked Meat Using Ambient Liquid Extraction Surface Analysis Mass Spectrometry
M. Montowska, M.R. Alexander, G.A. Tucker, D.A. Barrett
Anal Chem. 2014 Oct 21;86(20):10257-65. doi: 10.1021/ac502449w
In this Article, our previously developed ambient LESA-MS methodology is implemented to analyze five types of thermally treated meat species, namely, beef, pork, horse, chicken, and turkey meat, to select and identify heat-stable and species-specific peptide markers. In-solution tryptic digests of cooked meats were deposited onto a polymer surface, followed by LESA-MS analysis and evaluation using multivariate data analysis and tandem electrospray MS. The five types of cooked meat were clearly discriminated using principal component analysis and orthogonal partial least-squares discriminant analysis. 23 heat stable peptide markers unique to species and muscle protein were identified following data-dependent tandem LESA-MS analysis. Surface extraction and direct ambient MS analysis of mixtures of cooked meat species was performed for the first time and enabled detection of 10% (w/w) of pork, horse, and turkey meat and 5% (w/w) of chicken meat in beef, using the developed LESA-MS/MS analysis. The study shows, for the first time, that ambient LESA-MS methodology displays specificity sufficient to be implemented effectively for the analysis of processed and complex peptide digests. The proposed approach is much faster and simpler than other measurement tools for meat speciation; it has potential for application in other areas of meat science or food production.
CHIPSOFT 10.0 WITH DEVELOPERS KIT: Customized method development for the TriVersa Nanomate
ChipSoftX is an entirely new operating software for the TriVersa NanoMate automated nanoelectrospray source. Besides improvement in program compatibility with Windows and integration of existing software features, it also provides access to the new Developers Kit – a platform for customized method development with direct access to robot controls allowing entirely novel analysis workflows such as LESAPLUS.
Direct Tissue Profiling of Protein Complexes: Toward Native Mass Spectrometry Imaging
Native mass spectrometry seeks to probe noncovalent protein interactions in terms of protein quaternary structure, protein–protein and protein–ligand complexes. The ultimate goal is to link the understanding of protein interactions to the protein environment by visualizing the spatial distribution of noncovalent protein interactions within tissue. Previously, we have shown that noncovalently bound protein complexes can be directly probed via liquid extraction surface analysis from dried blood spot samples, where hemoglobin is highly abundant. Here, we show that the intact hemoglobin complex can be sampled directly from thin tissue sections of mouse liver and correlated to a visible vascular feature, paving the way for native mass spectrometry imaging.
R.L. Griffiths and H.J. Cooper Anal. Chem., 2016, 88 (1), pp 606–609
Liquid extraction surface analysis field asymmetric waveform ion mobility spectrometry mass spectrometry for the analysis of dried blood spots
Analyst, 2015, Accepted Manuscript DOI: 10.1039/C5AN00933B
Liquid extraction surface analysis (LESA) is a surface sampling technique that allows electrospray mass spectrometry analysis of a wide range of analytes directly from biological substrates. Here, we present LESA mass spectrometry coupled with high field asymmetric waveform ion mobility spectrometry (FAIMS) for the analysis of dried blood spots on filter paper. Incorporation of FAIMS in the workflow enables gas-phase separation of lipid and protein molecular classes, enabling analysis of both haemoglobin and a range of lipid (phosphatidylcholine or phosphatidylethanolamine, and sphingomyelin species) from a single extraction sample. The work has implications for multiplexed clinical assays of multiple analytes.
Direct Analysis of Intact Proteins from Escherichia coli Colonies by Liquid Extraction Surface Analysis Mass Spectrometry
Randall EC, Bunch J, Cooper HJ; Anal Chem. 2014 Nov 4;86(21):10504-10. doi: 10.1021/ac503349d. Epub 2014 Oct 23
Top-down identification of proteins by liquid extraction surface analysis (LESA) mass spectrometry has previously been reported for tissue sections and dried blood spot samples. Here, we present a modified “contact” LESA method for top-down analysis of proteins directly from living bacterial colonies grown in Petri dishes,without any sample pretreatment. It was possible to identify a number of proteins by use of collision-induced dissociation tandem mass spectrometry followed by searches of the data against an E. coli protein database. The proteins identified suggest that the method may provide insight into the bacterial response to environmental conditions. Moreover, the results show that the “contact” LESA approach results in a smaller sampling area than typical LESA, which may have implications for spatial profiling.
Native Liquid Extraction Surface Analysis Mass Spectrometry: Analysis of Noncovalent Protein Complexes Directly from Dried Substrates
Martin NJ, Griffiths RL, Edwards RL, Cooper HJ. J Am Soc Mass Spectrom. 2015 May 20. [Epub ahead of print]
Liquid extraction surface analysis (LESA) mass spectrometry is a promising tool for the analysis of intact proteins from biological substrates. Here, we demonstrate native LESA mass spectrometry of noncovalent protein complexes of myoglobin and hemoglobin from a range of surfaces. Holomyoglobin, in which apomyoglobin is noncovalently bound to the prosthetic heme group, was observed following LESA mass spectrometry of myoglobin dried onto glass and polyvinylidene fluoride surfaces. Tetrameric hemoglobin [(αβ)2 4H] was observed following LESA mass spectrometry of hemoglobin dried onto glass and polyvinylidene fluoride (PVDF) surfaces, and from dried blood spots (DBS) on filter paper. Heme-bound dimers and monomers were also observed. The ‘contact’ LESA approach was particularly suitable for the analysis of hemoglobin tetramers from DBS.
Quantitative spatial analysis of the mouse brain lipidome by pressurized liquid extraction surface analysis (PLESA)
Reinaldo Almeida, Zane Berzina, Eva C. Arnspang, Jan Baumgart, Johannes Vogt, Robert Nitsch, and Christer S. Ejsing
Anal. Chem., Just Accepted Manuscript
DOI: 10.1021/ac503627z
Publication Date (Web): December 30, 2014
Copyright © 2014 American Chemical Society
Here we describe a novel surface sampling technique termed pressurized liquid extraction surface analysis (PLESA), which in combination with a dedicated high resolution shotgun lipidomics routine enables both quantification and in-depth structural characterization of molecular lipid species extracted directly from tissue sections.
Using the TriVersa NanoMate with LESA for Analyte Profiling in Material Science
Surface analysis techniques have gained significant attention over the last couple of years with LESA being an interesting alternative to techniques such as SIMS or MALDI imaging. This note demonstrates practical applications for LESA in the material sciences.
