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Resin-Assisted Capture Coupled with Isobaric Tandem Mass Tag Labeling for Multiplexed Quantification of Protein Thiol Oxidation
Published on: June 21, 2021
Study of highly selective and efficient thiol derivatization using selenium reagents by mass spectrometry
1Center for Intelligent Chemical Instrumentation, Department of Chemistry and Biochemistry, Ohio University, Athens, Ohio 45701, USA.
Analytical Chemistry
|August 14, 2010
Summary
This study introduces a new method using selenium chemistry for labeling biological thiols. This rapid, selective, and reversible reaction is highly efficient for thiol identification and isolation in mass spectrometry (MS) applications.
Area of Science:
- Analytical Chemistry
- Biochemistry
- Organic Chemistry
Background:
- Biological thiols play crucial roles in cellular processes.
- Selective and efficient methods for thiol detection and analysis are essential in biochemical research.
- Current thiol labeling techniques often face limitations in selectivity, speed, or reversibility.
Purpose of the Study:
- To investigate a novel strategy for labeling biological thiols using selenium-nitrogen reagents.
- To evaluate the selectivity, speed, reversibility, and efficiency of this new thiol labeling method.
- To explore the potential applications of this method in mass spectrometry (MS)-based proteomics.
Main Methods:
- Systematic mass spectrometry (MS) investigation.
- Reaction of thiols with selenium-nitrogen reagents leading to Se-N bond cleavage and Se-S bond formation.
- Testing selectivity against 20 amino acids.
- Assessing reaction speed and reversibility with dithiothreitol.
- Analyzing dissociation behaviors of derivatized peptide ions via collision-induced dissociation (CID).
- Demonstrating applications in thiol peptide screening and quantification.
Main Results:
- The developed method exhibits high selectivity, reacting only with cysteine among 20 amino acids within seconds.
- The reaction is rapid, reversible, and highly efficient, achieving 100% conversion of protein beta-lactoglobulin A with ebselen in 30 s.
- Derivatized peptides can be recovered using dithiothreitol.
- Selenium derivatization allows for tunable dissociation behaviors of peptide ions in MS, aiding proteomics.
- Preliminary applications demonstrated successful rapid screening and quantification of thiols.
Conclusions:
- The novel selenium chemistry provides a powerful tool for selective thiol labeling and analysis.
- The method's selectivity, speed, and reversibility offer significant advantages for identifying and isolating thiols from complex biological mixtures.
- Tunable dissociation properties enhance its utility in mass spectrometry-based proteomics for thiol and disulfide bond analysis.
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02:33Preparation and Reactions of Thiols
Thiols are prepared using the hydrosulfide anion as a nucleophile in a nucleophilic substitution reaction with alkyl halides. For instance, bromobutane reacts with sodium hydrosulfide to give butanethiol.
02:26Preparation and Reactions of Sulfides
Sulfides are the sulfur analog of ethers, just as thiols are the sulfur analog of alcohol. Like ethers, sulfides also consist of two hydrocarbon groups bonded to the central sulfur atom. Depending upon the type of groups present, sulfides can be symmetrical or asymmetrical. Symmetrical sulfides can be prepared via an SN2 reaction between 2 equivalents of an alkyl halide and one equivalent of sodium sulfide.
01:21Mass Spectrometry: Complex Analysis
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01:33Peptide Identification Using Tandem Mass Spectrometry
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02:17Structure and Nomenclature of Thiols and Sulfides
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