Related Research Articles
Mass spectrometry (MS) is an analytical technique that is used to measure the mass-to-charge ratio of ions. The results are presented as a mass spectrum, a plot of intensity as a function of the mass-to-charge ratio. Mass spectrometry is used in many different fields and is applied to pure samples as well as complex mixtures.
Tandem mass spectrometry, also known as MS/MS or MS2, is a technique in instrumental analysis where two or more stages of analysis using one or more mass analyzer are performed with an additional reaction step in between these analyses to increase their abilities to analyse chemical samples. A common use of tandem MS is the analysis of biomolecules, such as proteins and peptides.
Electron-capture dissociation (ECD) is a method of fragmenting gas-phase ions for structure elucidation of peptides and proteins in tandem mass spectrometry. It is one of the most widely used techniques for activation and dissociation of mass selected precursor ion in MS/MS. It involves the direct introduction of low-energy electrons to trapped gas-phase ions.
Hydrogen–deuterium exchange is a chemical reaction in which a covalently bonded hydrogen atom is replaced by a deuterium atom, or vice versa. It can be applied most easily to exchangeable protons and deuterons, where such a transformation occurs in the presence of a suitable deuterium source, without any catalyst. The use of acid, base or metal catalysts, coupled with conditions of increased temperature and pressure, can facilitate the exchange of non-exchangeable hydrogen atoms, so long as the substrate is robust to the conditions and reagents employed. This often results in perdeuteration: hydrogen-deuterium exchange of all non-exchangeable hydrogen atoms in a molecule.
A peptide sequence tag is a piece of information about a peptide obtained by tandem mass spectrometry that can be used to identify this peptide in a protein database.
Electron-transfer dissociation (ETD) is a method of fragmenting multiply-charged gaseous macromolecules in a mass spectrometer between the stages of tandem mass spectrometry (MS/MS). Similar to electron-capture dissociation, ETD induces fragmentation of large, multiply-charged cations by transferring electrons to them. ETD is used extensively with polymers and biological molecules such as proteins and peptides for sequence analysis. Transferring an electron causes peptide backbone cleavage into c- and z-ions while leaving labile post translational modifications (PTM) intact. The technique only works well for higher charge state peptide or polymer ions (z>2). However, relative to collision-induced dissociation (CID), ETD is advantageous for the fragmentation of longer peptides or even entire proteins. This makes the technique important for top-down proteomics. The method was developed by Hunt and coworkers at the University of Virginia.
Protein mass spectrometry refers to the application of mass spectrometry to the study of proteins. Mass spectrometry is an important method for the accurate mass determination and characterization of proteins, and a variety of methods and instrumentations have been developed for its many uses. Its applications include the identification of proteins and their post-translational modifications, the elucidation of protein complexes, their subunits and functional interactions, as well as the global measurement of proteins in proteomics. It can also be used to localize proteins to the various organelles, and determine the interactions between different proteins as well as with membrane lipids.
Shotgun proteomics refers to the use of bottom-up proteomics techniques in identifying proteins in complex mixtures using a combination of high performance liquid chromatography combined with mass spectrometry. The name is derived from shotgun sequencing of DNA which is itself named after the rapidly expanding, quasi-random firing pattern of a shotgun. The most common method of shotgun proteomics starts with the proteins in the mixture being digested and the resulting peptides are separated by liquid chromatography. Tandem mass spectrometry is then used to identify the peptides.
Top-down proteomics is a method of protein identification that either uses an ion trapping mass spectrometer to store an isolated protein ion for mass measurement and tandem mass spectrometry (MS/MS) analysis or other protein purification methods such as two-dimensional gel electrophoresis in conjunction with MS/MS. Top-down proteomics is capable of identifying and quantitating unique proteoforms through the analysis of intact proteins. The name is derived from the similar approach to DNA sequencing. During mass spectrometry intact proteins are typically ionized by electrospray ionization and trapped in a Fourier transform ion cyclotron resonance, quadrupole ion trap or Orbitrap mass spectrometer. Fragmentation for tandem mass spectrometry is accomplished by electron-capture dissociation or electron-transfer dissociation. Effective fractionation is critical for sample handling before mass-spectrometry-based proteomics. Proteome analysis routinely involves digesting intact proteins followed by inferred protein identification using mass spectrometry (MS). Top-down MS (non-gel) proteomics interrogates protein structure through measurement of an intact mass followed by direct ion dissociation in the gas phase.
Quantitative proteomics is an analytical chemistry technique for determining the amount of proteins in a sample. The methods for protein identification are identical to those used in general proteomics, but include quantification as an additional dimension. Rather than just providing lists of proteins identified in a certain sample, quantitative proteomics yields information about the physiological differences between two biological samples. For example, this approach can be used to compare samples from healthy and diseased patients. Quantitative proteomics is mainly performed by two-dimensional gel electrophoresis (2-DE), preparative native PAGE, or mass spectrometry (MS). However, a recent developed method of quantitative dot blot (QDB) analysis is able to measure both the absolute and relative quantity of an individual proteins in the sample in high throughput format, thus open a new direction for proteomic research. In contrast to 2-DE, which requires MS for the downstream protein identification, MS technology can identify and quantify the changes.
Isobaric tags for relative and absolute quantitation (iTRAQ) is an isobaric labeling method used in quantitative proteomics by tandem mass spectrometry to determine the amount of proteins from different sources in a single experiment. It uses stable isotope labeled molecules that can be covalent bonded to the N-terminus and side chain amines of proteins.
A triple quadrupole mass spectrometer (TQMS), is a tandem mass spectrometer consisting of two quadrupole mass analyzers in series, with a (non-mass-resolving) radio frequency (RF)–only quadrupole between them to act as a cell for collision-induced dissociation. This configuration is often abbreviated QqQ, here Q1q2Q3.
Selected reaction monitoring (SRM), also called multiple reaction monitoring (MRM), is a method used in tandem mass spectrometry in which an ion of a particular mass is selected in the first stage of a tandem mass spectrometer and an ion product of a fragmentation reaction of the precursor ions is selected in the second mass spectrometer stage for detection.
In mass spectrometry, fragmentation is the dissociation of energetically unstable molecular ions formed from passing the molecules mass spectrum. These reactions are well documented over the decades and fragmentation patterns are useful to determine the molar weight and structural information of unknown molecules. Fragmentation that occurs in tandem mass spectrometry experiments has been a recent focus of research, because this data helps facilitate the identification of molecules.
Isobaric labeling is a mass spectrometry strategy used in quantitative proteomics. Peptides or proteins are labeled with chemical groups that have identical mass (isobaric), but vary in terms of distribution of heavy isotopes in their structure. These tags, commonly referred to as tandem mass tags, are designed so that the mass tag is cleaved at a specific linker region upon high-energy CID (HCD) during tandem mass spectrometry yielding reporter ions of different masses. The most common isobaric tags are amine-reactive tags. However, tags that react with cysteine residues and carbonyl groups have also been described. These amine-reactive groups go through N-hydroxysuccinimide (NHS) reactions, which are based around three types of functional groups. Isobaric labeling methods include tandem mass tags (TMT), isobaric tags for relative and absolute quantification (iTRAQ), mass differential tags for absolute and relative quantification, and dimethyl labeling. TMTs and iTRAQ methods are most common and developed of these methods. Tandem mass tags have a mass reporter region, a cleavable linker region, a mass normalization region, and a protein reactive group and have the same total mass.
Kevin Downard is a British - Australian academic scientist whose research specialises in the improving responses to infectious disease through the application and development of mass spectrometry and other molecular approaches in the life and medical sciences. Downard has over 35 years of experience in the field and has written over 145 lead-author scientific peer-reviewed journal publications, and two books including a textbook for the Royal Society of Chemistry and the first book to be published on the role of mass spectrometry in the study of protein interactions.
Proteogenomics is a field of biological research that utilizes a combination of proteomics, genomics, and transcriptomics to aid in the discovery and identification of peptides. Proteogenomics is used to identify new peptides by comparing MS/MS spectra against a protein database that has been derived from genomic and transcriptomic information. Proteogenomics often refers to studies that use proteomic information, often derived from mass spectrometry, to improve gene annotations. The utilization of both proteomics and genomics data alongside advances in the availability and power of spectrographic and chromatographic technology led to the emergence of proteogenomics as its own field in 2004.
Collision-induced dissociation (CID), also known as collisionally activated dissociation (CAD), is a mass spectrometry technique to induce fragmentation of selected ions in the gas phase. The selected ions are usually accelerated by applying an electrical potential to increase the ion kinetic energy and then allowed to collide with neutral molecules. In the collision, some of the kinetic energy is converted into internal energy which results in bond breakage and the fragmentation of the molecular ion into smaller fragments. These fragment ions can then be analyzed by tandem mass spectrometry.
In mass spectrometry, de novo peptide sequencing is the method in which a peptide amino acid sequence is determined from tandem mass spectrometry.
References
- ↑ Doerr, Allison (2014). "DIA mass spectrometry". Nature Methods. 12 (1): 35. doi:10.1038/nmeth.3234. ISSN 1548-7091. S2CID 83712891.
- ↑ Law, Kai Pong; Lim, Yoon Pin (2014). "Recent advances in mass spectrometry: data independent analysis and hyper reaction monitoring". Expert Review of Proteomics. 10 (6): 551–566. doi:10.1586/14789450.2013.858022. ISSN 1478-9450. PMID 24206228. S2CID 29969570.
- ↑ Chapman, John D.; Goodlett, David R.; Masselon, Christophe D. (2014). "Multiplexed and data-independent tandem mass spectrometry for global proteome profiling". Mass Spectrometry Reviews. 33 (6): 452–470. Bibcode:2014MSRv...33..452C. doi:10.1002/mas.21400. ISSN 0277-7037. PMID 24281846.
- 1 2 Purvine, Samuel; Eppel, Jason-Thomas; Yi, Eugene C.; Goodlett, David R. (2003). "Shotgun collision-induced dissociation of peptides using a time of flight mass analyzer". Proteomics. 3 (6): 847–850. doi:10.1002/pmic.200300362. ISSN 1615-9853. PMID 12833507. S2CID 31639003.
- 1 2 3 Plumb, Robert S.; Johnson, Kelly A.; Rainville, Paul; Smith, Brian W.; Wilson, Ian D.; Castro-Perez, Jose M.; Nicholson, Jeremy K. (2006). "UPLC/MSE; a new approach for generating molecular fragment information for biomarker structure elucidation". Rapid Communications in Mass Spectrometry. 20 (13): 1989–1994. Bibcode:2006RCMS...20.1989P. doi:10.1002/rcm.2550. ISSN 0951-4198. PMID 16755610.
- ↑ Venable JD, Dong MQ, Wohlschlegel J, Dillin A, Yates JR (2004). "Automated approach for quantitative analysis of complex peptide mixtures from tandem mass spectra". Nat. Methods. 1 (1): 39–45. doi:10.1038/nmeth705. PMID 15782151. S2CID 9780065.
- ↑ Gillet LC, Navarro P, Tate S, Röst H, Selevsek N, Reiter L, Bonner R, Aebersold R (2012). "Targeted data extraction of the MS/MS spectra generated by data-independent acquisition: a new concept for consistent and accurate proteome analysis". Mol. Cell. Proteomics. 11 (6): O111.016717. doi: 10.1074/mcp.O111.016717 . PMC 3433915 . PMID 22261725.