scholarly journals Mass spectrometric method for the unambiguous profiling of cellular dynamic glycosylation

2020 ◽  
Author(s):  
Asif Shajahan ◽  
Nitin T. Supekar ◽  
Han Wu ◽  
Amberlyn M. Wands ◽  
Ganapati Bhat ◽  
...  
Keyword(s):  
Direct Detection ◽  
Sugar Metabolism ◽  
Cellular Level ◽  
Spectrometric Method ◽  
Mass Spectrometric Method ◽  
Post Translational Modification ◽  
Functional Studies ◽  
External Stimuli ◽  
Processing Steps ◽  
Subsequent Incorporation

ABSTRACTVarious biological processes at the cellular level are regulated by glycosylation which is a highly micro-heterogeneous post-translational modification (PTM) on proteins and lipids. The dynamic nature of glycosylation can be studied through bio-orthogonal tagging of metabolically engineered non-natural sugars into glycan epitopes. However, this approach possesses a significant drawback due to non-specific background reactions and ambiguity of non-natural sugar metabolism. Here we report a tag-free strategy for their direct detection by glycoproteomics and glycomics using mass spectrometry. The method dramatically simplifies the detection of non-natural functional group bearing monosaccharides installed through promiscuous sialic acid, GalNAc, and GlcNAc biosynthetic pathways. Multistage enrichment of glycoproteins by cellular fractionation, subsequent ZIC-HILIC based glycopeptide enrichment, and a spectral enrichment algorithm for the MS data processing enabled direct detection of non-natural monosaccharides that are incorporated at low abundance on the N/O-glycopeptides along with their natural counterparts. Our approach allowed the detection of both natural and non-natural sugar bearing glycopeptides, N and O-glycopeptides, differentiation of non-natural monosaccharide types on the glycans and also their incorporation efficiency through quantitation. Through this we could deduce some interconversion of monosaccharides during their processing through glycan salvage pathway and subsequent incorporation into glycan chains. The study of glycosylation dynamics through this method can be conducted in high throughput as few sample processing steps are involved, enabling understanding of glycosylation dynamics under various external stimuli and thereby could bolster the use of metabolic glycan engineering in glycosylation functional studies.

scholarly journals Facultative protein selenation regulates redox sensitivity, adipose tissue thermogenesis, and obesity

2020 ◽  
Vol 117 (20) ◽  
pp. 10789-10796 ◽  
Author(s):  
Mark P. Jedrychowski ◽  
Gina Z. Lu ◽  
John Szpyt ◽  
Marco Mariotti ◽  
Ryan Garrity ◽  
...  
Keyword(s):  
Adipose Tissue ◽  
Direct Detection ◽  
Uncoupling Protein ◽  
Spectrometric Method ◽  
Mass Spectrometric Method ◽  
Biological Processes ◽  
Uncoupling Protein 1 ◽  
Redox Sensitivity ◽  
Cysteine Thiols ◽  
Regulatory Sites

Oxidation of cysteine thiols by physiological reactive oxygen species (ROS) initiates thermogenesis in brown and beige adipose tissues. Cellular selenocysteines, where sulfur is replaced with selenium, exhibit enhanced reactivity with ROS. Despite their critical roles in physiology, methods for broad and direct detection of proteogenic selenocysteines are limited. Here we developed a mass spectrometric method to interrogate incorporation of selenium into proteins. Unexpectedly, this approach revealed facultative incorporation of selenium as selenocysteine or selenomethionine into proteins that lack canonical encoding for selenocysteine. Selenium was selectively incorporated into regulatory sites on key metabolic proteins, including as selenocysteine-replacing cysteine at position 253 in uncoupling protein 1 (UCP1). This facultative utilization of selenium was initiated by increasing cellular levels of organic, but not inorganic, forms of selenium. Remarkably, dietary selenium supplementation elevated facultative incorporation into UCP1, elevated energy expenditure through thermogenic adipose tissue, and protected against obesity. Together, these findings reveal the existence of facultative protein selenation, which correlates with impacts on thermogenic adipocyte function and presumably other biological processes as well.

Tandem Mass Spectrometric Evaluation of Core Structures of Aromatic Compounds after Catalytic Deoxygenation

2017 ◽  
Author(s):  
Xueming Dong
Keyword(s):  
Aromatic Compounds ◽  
Supported Catalyst ◽  
Mass Spectrometric ◽  
Spectrometric Method ◽  
Mass Spectrometric Method ◽  
Aromatic Rings ◽  
Tandem Mass Spectrometric ◽  
Catalytic Deoxygenation ◽  
Oxygen Atoms

Catalytic deoxygenation of coal enhances the stability and combustion performance of coal-derived liquids. However, determination of the selectivity of removal of oxygen atoms incorporated in or residing outside of aromatic rings is challenging. This limits the ability to evaluate the success of catalytic deoxygenation processes. A mass spectrometric method, in-source collision-activated dissociation (ISCAD), combined with high resolution product ion detection, is demonstrated to allow the determination of whether the oxygen atoms in aromatic compounds reside outside of aromatic rings or are part of the aromatic system, because alkyl chains can be removed from aromatic cores via ISCAD. Application of this method for the analysis of a subbituminous coal treated using a supported catalyst revealed that the catalytic treatment reduced the number of oxygen-containing heteroaromatic rings but not the number of oxygen atoms residing outside the aromatic rings.<br>

Tandem Mass Spectrometric Evaluation of Core Structures of Aromatic Compounds after Catalytic Deoxygenation

2017 ◽  
Author(s):  
Xueming Dong
Keyword(s):  
Aromatic Compounds ◽  
Supported Catalyst ◽  
Mass Spectrometric ◽  
Spectrometric Method ◽  
Mass Spectrometric Method ◽  
Aromatic Rings ◽  
Tandem Mass Spectrometric ◽  
Catalytic Deoxygenation ◽  
Oxygen Atoms

Catalytic deoxygenation of coal enhances the stability and combustion performance of coal-derived liquids. However, determination of the selectivity of removal of oxygen atoms incorporated in or residing outside of aromatic rings is challenging. This limits the ability to evaluate the success of catalytic deoxygenation processes. A mass spectrometric method, in-source collision-activated dissociation (ISCAD), combined with high resolution product ion detection, is demonstrated to allow the determination of whether the oxygen atoms in aromatic compounds reside outside of aromatic rings or are part of the aromatic system, because alkyl chains can be removed from aromatic cores via ISCAD. Application of this method for the analysis of a subbituminous coal treated using a supported catalyst revealed that the catalytic treatment reduced the number of oxygen-containing heteroaromatic rings but not the number of oxygen atoms residing outside the aromatic rings.<br>

scholarly journals Mass Spectrometric Calibration Procedure for Real-Time Detection of Lighter Hydrocarbons

Energies ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 2123
Author(s):  
Makuachukwu F. Mbaegbu ◽  
Puspa L. Adhikari ◽  
Ipsita Gupta ◽  
Mathew Rowe
Keyword(s):  
Real Time ◽  
Mass Spectrometer ◽  
Calibration Procedure ◽  
Mass Spectrometric ◽  
Spectrometric Method ◽  
Mass Selection ◽  
Mass Spectrometric Method ◽  
Mass Spectrometers ◽  
Drilling Rig

Determining gas compositions from live well fluids on a drilling rig is critical for real time formation evaluation. Development and utilization of a reliable mass spectrometric method to accurately characterize these live well fluids are always challenging due to lack of a robust and effectively selective instrument and procedure. The methods currently utilized need better calibration for the characterization of light hydrocarbons (C1–C6) at lower concentrations. The primary goal of this research is to develop and optimize a powerful and reliable analytical method to characterize live well fluid using a quadruple mass spectrometer (MS). The mass spectrometers currently being used in the field have issues with detection, spectra deconvolution, and quantification of analytes at lower concentrations (10–500 ppm), particularly for the lighter (<30 m/z) hydrocarbons. The objectives of the present study are thus to identify the detection issues, develop and optimize a better method, calibrate and QA/QC the MS, and validate the MS method in lab settings. In this study, we used two mass spectrometers to develop a selective and precise method to quantitatively analyze low level lighter analytes (C1–C6 hydrocarbons) with masses <75 m/z at concentrations 10–500 ppm. Our results suggest that proper mass selection like using base peaks with m/z 15, 26, 41, 43, 73, and 87, respectively, for methane, ethane, propane, butane, pentane, and hexane can help detect and accurately quantify hydrocarbons from gas streams. This optimized method in quadrupole mass spectrometer (QMS) will be invaluable for early characterization of the fluid components from a live hydrocarbon well in the field in real time.

scholarly journals Development of a mass spectrometric method to quantitate platelet activating factor in mouse urine.

1989 ◽  
Vol 30 (12) ◽  
pp. 1977-1981
Author(s):  
E Benfenati ◽  
D Macconi ◽  
M Noris ◽  
G Icardi ◽  
L Bettazzoli ◽  
...  
Keyword(s):  
Platelet Activating Factor ◽  
Mass Spectrometric ◽  
Spectrometric Method ◽  
Mass Spectrometric Method ◽  
Mouse Urine

scholarly journals Development and validation of a liquid chromatography-tandem mass spectrometric method for the determination of lenalidomide in human plasma and its application on bioequivalence studies

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
R. Gopinath ◽  
S. T. Narenderan ◽  
M. Kumar ◽  
B. Babu
Keyword(s):  
Liquid Chromatography ◽  
Human Plasma ◽  
Internal Standard ◽  
Spectrometric Method ◽  
Tandem Mass ◽  
Mass Spectrometric Method ◽  
Mass Detection ◽  
Triple Quadrupole Mass Spectrometer ◽  
Liquid Chromatography Tandem Mass ◽  
Tandem Mass Spectrometric

AbstractA simple, sensitive, and specific liquid chromatography-tandem mass spectrophotometry (LC-MS/MS) method was developed and validated for the quantification of lenalidomide in human plasma. The separation was carried out on a symmetry, C18, 5-μm (50 × 4.6 mm) column as stationary phase and with an isocratic mobile phase of 0.1% formic acid in water-methanol in the ratio of (15:85, v/v) at a flow rate of 0.5 mL/min. Protonated ions formed by electrospray ionization in the positive mode were used to detect analyte and fluconazole (internal standard). The mass detection was made by monitoring the fragmentation of m/z 260.1/148.8 for lenalidomide and m/z 307.1/238.0 for internal standard on a triple quadrupole mass spectrometer. The developed method was validated over the concentration range of 10–1000 ng/mL for lenalidomide in human plasma with a correlation coefficient (r2) was 0.9930. The accuracy and precision values obtained from six different sets of quality control samples analyzed on separate occasions ranged from 99.41 to 106.97% and 2.88 to 4.22%, respectively. Mean extraction recoveries were 98.06% and 88.78% for the analyte and IS, respectively. The developed method was successfully applied for analyzing lenalidomide in human plasma samples.

Mass spectrometric method of analysing saturated cyclic sulphides

1969 ◽  
Vol 9 (1) ◽  
pp. 73-82
Author(s):  
Y BRODSKII ◽  
R KHMELNITSKII ◽  
A POLYAKOVA
Keyword(s):  
Mass Spectrometric ◽  
Spectrometric Method ◽  
Mass Spectrometric Method
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