scholarly journals A well-ordered nanoflow LC-MS/MS approach for proteome profiling using 200 cm long micro pillar array columns

2018 ◽  
Author(s):  
Jeff Op De Beeck ◽  
Jarne Pauwels ◽  
Natalie Van Landuyt ◽  
Paul Jacobs ◽  
Wim De Malsche ◽  
...  

ABSTRACTIn bottom-up proteomics, capillaries up to 75 cm long with internal diameters of 50 to 100 µm packed with sub-2-µm C18-functionalized particles are routinely used in combination with high-resolution mass spectrometry. Unlike such conventional liquid chromatography (LC) columns, micro pillar array columns (µPAC™) are fabricated using micromachining technology, resulting in perfectly ordered chromatographic separation beds, leading to a minimized analyte dispersion while column permeability is increased by one order of magnitude. This allows using very long columns (up to 200 cm) at only a fraction of the pressure needed to operate packed bed columns. To validate µPAC™ column performances, different amounts of tryptic digests of HEK293T cell lysates were prepared and separated using a 200 cm µPAC™ column or a 40 cm long conventional column. Using an Orbitrap Elite instrument, on average 25% more proteins were identified with the µPAC™ column. Moreover, the rate at which the peak width increases with gradient time is much lower on the µPAC™ column. For a 10-hour long gradient, average peak widths below 0.5 min were observed, resulting in consistent identification of over 5,000 proteins. Combining long solvent gradients and this new type of LC column, substantial improvements in proteome coverage could be obtained. Finally, we demonstrated high reproducibility and durability of the µPAC™ column. Data are available via ProteomeXchange with identifiers PXD011547 and PXD013235.

2021 ◽  
Author(s):  
Karel Stejskal ◽  
Jeff Op de Beeck ◽  
Manuel Matzinger ◽  
Gerhard Duernberger ◽  
Oleksandr Boychenko ◽  
...  

In the field of LC-MS based proteomics, increases in sampling depth and proteome coverage have mainly been accomplished by rapid advances in mass spectrometer technology. The comprehensiveness and quality of data that can be generated do however also depend on the performance provided by nano liquid chromatography (nanoLC) separations. Proper selection of reversed-phase separation columns can be of paramount importance to provide the MS instrument with peptides at the highest possible concentration and separated at the highest possible resolution. As an alternative to traditional packed bed LC column technology that uses beads packed into capillary tubing, we present a novel LC column format based on photolithographic definition and Deep Reactive Ion Etching (DRIE) into silicon wafers. With a next generation pillar array column designed for universal use in bottom-up proteomics, the critical dimensions of the stationary phase support structures have been reduced by a factor of 2 to provide further increases in separation power. To demonstrate the potential for single-shot proteomics workflows, we report on a series of optimization and benchmarking experiments where we combine LC separation on a new generation of pillar array columns using Vanquish Neo UHPLC with fast Orbitrap Tribrid MS data-dependent acquisition (DDA) and High-Field Asymmetric Waveform Ion Mobility Spectrometry (FAIMS). In addition to providing superior proteome coverage, robust operation over more than 1 month with a single nanoESI emitter and reduction of the column related sample carry over are additional figures of merit that can help improve proteome research sensitivity, productivity and standardization.


2020 ◽  
Author(s):  
Jie Cheng ◽  
Yuchen Tang ◽  
Baoquan Bao ◽  
Ping Zhang

<p><a></a><a></a><a></a><a><b>Objective</b></a>: To screen all compounds of Agsirga based on the HPLC-Q-Exactive high-resolution mass spectrometry and find potential inhibitors that can respond to 2019-nCoV from active compounds of Agsirga by molecular docking technology.</p> <p><b>Methods</b>: HPLC-Q-Exactive high-resolution mass spectrometry was adopted to identify the complex components of Mongolian medicine Agsirga, and separated by the high-resolution mass spectrometry Q-Exactive detector. Then the Orbitrap detector was used in tandem high-resolution mass spectrometry, and the related molecular and structural formula were found by using the chemsipider database and related literature, combined with precise molecular formulas (errors ≤ 5 × 10<sup>−6</sup>) , retention time, primary mass spectra, and secondary mass spectra information, The fragmentation regularities of mass spectra of these compounds were deduced. Taking ACE2 as the receptor and deduced compounds as the ligand, all of them were pretreated by discover studio, autodock and Chem3D. The molecular docking between the active ingredients and the target protein was studied by using AutoDock molecular docking software. The interaction between ligand and receptor is applied to provide a choice for screening anti-2019-nCoV drugs.</p> <p><b>Result</b>: Based on the fragmentation patterns of the reference compounds and consulting literature, a total of 96 major alkaloids and stilbenes were screened and identified in Agsirga by the HPLC-Q-Exactive-MS/MS method. Combining with molecular docking, a conclusion was got that there are potential active substances in Mongolian medicine Agsirga which can block the binding of ACE2 and 2019-nCoV at the molecular level.</p>


2020 ◽  
Vol 86 (8) ◽  
pp. 23-31
Author(s):  
V. G. Amelin ◽  
D. S. Bolshakov

The goal of the study is developing a methodology for determination of the residual amounts of quaternary ammonium compounds (QAC) in food products by UHPLC/high-resolution mass spectrometry after water-acetonitrile extraction of the determined components from the analyzed samples. The identification and determination of QAC was carried out on an «UltiMate 3000» ultra-high-performance liquid chromatograph (Thermo Scientific, USA) equipped with a «maXis 4G» high-resolution quadrupole-time-of-flight mass spectrometric detector and an ion spray «ionBooster» source (Bruker Daltonics, Germany). Samples of milk, cheese (upper cortical layer), dumplings, pork, chicken skin and ground beef were used as working samples. Optimal conditions are specified for chromatographic separation of the mixture of five QAC, two of them being a mixture of homologues with a linear structure (including isomeric forms). The identification of QAC is carried out by the retention time, exact mass of the ions, and coincidence of the mSigma isotopic distribution. The limits for QAC detection are 0.1 – 0.5 ng/ml, the determination limits are 1 ng/ml for aqueous standard solutions. The determinable content of QAC in food products ranges within 1 – 100 ng/g. The results of analysis revealed the residual amount of QAC present in all samples, which confirms data of numerous sources of information about active use of QAC-based disinfectants in the meat and dairy industry. The correctness of the obtained results is verified by introduction of the additives in food products at a level of 10 ng/g for each QAC. The relative standard deviation of the analysis results does not exceed 0.18. The duration of the analysis is 30 – 40 min.


The concept of exposome has received increasing discussion, including the recent Special Issue of Science –"Chemistry for Tomorrow's Earth,” about the feasibility of using high-resolution mass spectrometry to measure exposome in the body, and tracking the chemicals in the environment and assess their biological effect. We discuss the challenges of measuring and interpreting the exposome and suggest the survey on the life course history, built and ecological environment to characterize the sample of study, and in combination with remote sensing. They should be part of exposomics and provide insights into the study of exposome and health.


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