Subject Search: Mass Spectrometry

Specific labeling, enrichment and quantitation of S-nitrosylated peptides using iodoTMT reagents

S-nitrosylation is a post-translational modification (PTM) that regulates numerous processes, including cellular proliferation, apoptosis, smooth muscle relaxation, neurotransmitter release, and differentiation (Ref.1). During S-nitrosylation, nitric oxide radicals react with free cysteine thiols to produce an S-NO adduct that alters protein activity. Unlike other PTMs such as phoshorylation and acetylation, S-nitrosylation does not appear to have

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Mass spectrometry sample preparation procedure for protein samples

Mass spectrometry (MS) has become a prominent technique in biological research for the identification, characterization, and quantification of proteins (Ref. 1). Shotgun proteomics is a commonly used strategy to identify proteins in complex mixtures by digesting proteins at specific amino acids into peptides that can be separated and identified by mass spectrometry (Ref.2). In order

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Quantitative cancer stem cell phosphoprotein profiling

Cancer stem cells (CSCs) are hypothesized to provide a repository of cells that are refractory to chemotherapeutic agents developed for treating differentiated tumor cells. (Ref.1) A glioblastoma cancer stem cell line (NSC11) differentiates from a pluripotent state to a progenitor cell-like state when stimulated with WP1193, an inhibitor of STAT3 phosphorylation. (Ref.2) In this study,

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Cell-free protein expression for generating stable isotope-labeled proteins

Stable isotope-labeled peptides are routinely used as internal standards for mass spectrometry (MS) quantification of enzymatically digested protein samples. However, stable isotope-labeled proteins are considered better standards because they control for MS sample-preparation loss and digestion efficiency variation.1 Traditional in vivo expression systems, such as 15N-labeled E. coli or SILAC (i.e., stable isotope labeling using

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Selective enrichment of sialylated glycopeptides

Sialylated glycans and glycoproteins are implicated in numerous physiopathological mechanisms and used in applications for biotherapeutic development. Mass spectrometry (MS) has become one of the most powerful tools for glycopeptide analysis; however, structural characterization of sialylated glycopeptides remains analytically challenging because of their low abundance, and acidic and hydrophilic properties. In principle, targeted enrichment of

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Peptide retention time calibration mixture

The Thermo Scientific Pierce Peptide Retention Time Calibration Mixture enables retention time prediction for peptides on reversed-phase columns. This calibration mixture is useful for predicting peptide retention within a complex mixture for mass spectrometry (MS) analysis.1-3 By testing the mixture throughout the lifetime of a column, it is possible to monitor performance characteristics during column

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Mass spec calibration solutions

Routine calibration of mass spectrometers is required for optimal performance. Our new calibration solutions for Thermo Scientific Mass Spectrometers are ready-to-use liquid formulations for quick and easy instrument calibration.

Calibration solutions for Thermo Scientific Ion Trap and Orbitrap Mass Spectrometers

Calibration of Thermo Scientific Ion Trap and Orbitrap Mass Spectrometers is required for proper instrument

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Develop SRM and MRM assays

Thermo Scientific PEPotec SRM Peptide Libraries are fully synthetic, crude peptides customized for the development of mid- to high-throughput single-reaction monitoring (SRM) and multiple-reaction monitoring (MRM) assays in quantitative mass spectrometry (MS) workflows. The study of proteomes, sub-proteomes and protein pathways often requires quantitative MS analysis that depends on the identification and validation of SRM

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