Liquid Extraction Surface Analysis for Native Mass Spectrometry: Protein Complexes and Ligand Binding

Published by the International Journal of Mass Spectrometry

Native liquid extraction surface analysis (LESA) mass spectrometry enables the direct sampling of protein complexes from a solid surface. We have previously demonstrated native LESA mass spectrometry of holomyoglobin (~17 kDa) from glass slides and tetrameric haemoglobin (~64 kDa) from dried blood spots and thin tissue sections. Here, we further explore the capabilities of this
emerging technique by investigating a range of proteins which exist in various oligomeric states in vivo.

Victor A.Mikhailov, Rian L.Griffiths, Helen J.Cooper,
Liquid Extraction Surface Analysis for Native Mass Spectrometry: Protein
Complexes and Ligand Binding, International Journal of Mass Spectrometry
http://dx.doi.org/10.1016/j.ijms.2016.09.011

Analysis of urine, oral fluid and fingerprints by liquid extraction surface analysis coupled to high resolution MS and MS/MS – opportunities for forensic and biomedical science

Published by the Royal Society of Chemistry

Liquid Extraction Surface Analysis (LESA) is a new, high throughput tool for ambient mass spectrometry. A solvent droplet is deposited from a pipette tip onto a surface and maintains contact with both the surface and the pipette tip for a few seconds before being re-aspirated. The technique is particularly suited to the analysis of trace materials on surfaces due to its high sensitivity and low volume of sample removal. In this work, we assess the suitability of LESA for obtaining detailed chemical profiles of fingerprints, oral fluid and urine, which may be used in future for rapid medical diagnostics or metabolomics studies. We further show how LESA can be used to detect illicit drugs and their metabolites in urine, oral fluid and fingerprints. This makes LESA a potentially useful tool in the growing field of fingerprint chemical analysis, which is relevant not only to forensics but also to medical diagnostics. Finally, we show how LESA can be used to detect the explosive material RDX in contaminated artificial fingermarks.

Myc Expression Drives Aberrant Lipid Metabolism in Lung Cancer

Published by the National Center for Biotechnology Information

MYC-mediated pathogenesis in lung cancer continues to attract interest for new therapeutic strategies. In this study, we describe a transgenic mouse model of KRAS-driven lung adenocarcinoma that affords reversible activation of MYC, used here as a tool for lipidomic profiling of MYC-dependent lung tumors formed in this model. Advanced mass spectrometric imaging and surface analysis techniques were used to characterize the spatial and temporal changes in lipid composition in lung tissue. We found that normal lung tissue was characterized predominantly by saturated phosphatidylcholines and phosphatidylglycerols, which are major lipid components of pulmonary surfactant. In contrast, tumor tissues displayed an increase in phosphatidylinositols and arachidonate-containing phospholipids that can serve as signaling precursors.

Lipid Species from Brain Tissue Sections Using LESA PLUS Liquid Extraction Surface Analysis PLUS LC Separation

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.

University of Hull, Chemistry Department

Q: WHAT IS THE FOCUS OF YOUR LAB’S RESEARCH?

A: My group are actively researching the application of mass spectrometry to a range of problems in both chemical and biomedical science. In particular we are involved in the application of mass spectrometry based proteomics for label free quantitation of proteins from human tissue samples and also in the identification of trace analytes from environmental samples. We are also investigating the synthesis of novel co-polymeric monolithic phases for sample extraction and separation.

Q: WHAT WAS YOUR PREVIOUS WORK FLOW OR CHALLENGES?

A: The Chemistry Department at Hull have long recognised the need for practical training on a wide range of chemical instrumentation. In particular we recognise the requirement from many companies in the pharmaceutical and fine chemical sectors for practical training in GC/MS and LC/MS. The Advion expressionL compact mass spectromater (CMS) was purchased to provide such training at an undergraduate level and has been incorporated into the range of instrumental analysis practicals for final year students. The expressionL CMS fits tidily on the bench-top next to the HPLC system and gives students the chance experience at first hand the use of LCMS as an analytical technique. The ease of use and robust nature of the system means that the expressionL CMS lends itself to the undergraduate laboratory where users will not be experts in mass spectrometry at this point in their careers.

Q: WHY DID YOU INCORPORATE THE EXPRESSION CMS INTO YOUR LABORATORY?

A: We use the expressionL CMS to give undergraduate students practical experience of using LC/MS to prepare and analyse a ‘mock’ urine sample. The sample has to be prepared by adding the internal standard and extracting the analytes using Solid Phase Extraction (SPE) to obtain a sample suitable for LC/MS analysis. The aim is to identify and quantify the compounds found in the sample by reference to the internal standard added. The HPLC separation is a rapid 10 min gradient elution and the ability to incorporate the data from the UV detector into the MS data provides an additional benefit. Purchasing the expression L CMS has allowed us to provide practical training in LC/MS for our undergraduate students at a time when prospective employers are actively seeking such skills.

Qualitative Analysis of Commonly Abused Drugs by LC/MS on the expression® CMS

D. Tranchemontagne, N. Sousou, S. J. Prosser, J.D. Henion – Advion, Inc. & S. Orlowicz, S. Sadjadi, L. Snow – PhenoLogix

The Advion Interchim Scientific expression® Compact Mass Spectrometer (CMS) coupled with Liquid Chromatography (LC) was used as a qualitative screening tool. This application note will demonstrate the screening of various drugs, including amphetamines, benzodiazepines, antidepressants, opiates and opioid drugs as well as their common metabolites. It will show that the expression® CMS can easily be implemented in a doctor’s office to provide fast and easy drug screening.

LESA plus: Liquid Extraction Surface Analysis PLUS LC Separation

The Liquid Extraction Surface Analysis (LESA) capability of the TriVersa NanoMate enables simple, direct nanoESI mass spectrometric analysis from a variety of surfaces.

The new LESAPLUS allows for automated LESA experiments plus additional nano-LC separation through the ChipSoftX operating software with Developers Kit. This enhancement is ideal for direct tissue analysis.

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

 

Rian Griffiths,   Alex Dexter,   Andrew Creese and   Helen J Cooper  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.