Electron-capture dissociation
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.[1][2]
History
Electron-capture dissociation was developed by Roman Zubarev and Neil Kelleher while in Fred McLafferty's lab at Cornell University. Irradiation of melittin 4+ ions and ubiquitin 10+ ions (trapped in FT-MS cell) by laser pulses not only resulted in peculiar c', z fragmentation but also charge reduction. It was suggested that if FT cell is modified to trap cations and electrons simultaneously, secondary electrons emitted by UV photons increases the charge reduction effect and c′, z• fragmentation. Replacing UV laser with EI source led to the development of this new technique.[3]
Principles
Electron-capture dissociation typically involves a multiply protonated molecule M interacting with a free electron to form an odd-electron ion. Liberation of the electric potential energy results in fragmentation of the product ion.
- .
Rate of electron capture dissociation not only depends on the frequency of ion–electron fragmentation reactions but also on the number of ions in an ion–electron interaction volume. Electron current density and cross-section of ECD is directly proportional to fragmentation frequency.[4][5] An indirectly heated dispenser cathode used as an electron source results in larger electron current and larger emitting surface area.[6][7]
ECD devices can be of two forms. It can trap analyte ions during the ECD stage or can undergo flow through mode where dissociation takes place as analyte ions flows continuously through the ECD region. Flow through mode has advantage over other mode because nearly all the analyte ion beam is used. However, that decreases the efficiency of ECD for flow through mode.[8]
ECD produces significantly different types of fragment ions (although primarily c- and z-type, b-ions have been identified in ECD[9]) than other MS/MS fragmentation methods such as electron-detachment dissociation (EDD) (primarily a and x types),[10][11][12] collision-induced dissociation (CID) (primarily b[13] and y type) and infrared multiphoton dissociation. CID and IRMPD introduce internal vibrational energy in some way or another, causing loss of post-translational modifications during fragmentation. In ECD, unique fragments (and complementary to CID) are observed,[14] and the ability to fragment whole macromolecules effectively has been promising.
Although ECD is primarily used in Fourier transform ion cyclotron resonance mass spectrometry,[15] investigators have indicated that it has been successfully used in an ion-trap mass spectrometer.[16][17][18] ECD can also do rapid integration of multiple scans in FTICR-MS if put in a combination with external accumulation.[6]
ECD is a recently introduced MS/MS fragmentation technique and is still being investigated.[19][20] The mechanism of ECD is still under debate but appears not to necessarily break the weakest bond and is therefore thought to be a fast process (nonergodic) where energy is not free to relax intramolecularly. Suggestions have been made that radical reactions initiated by the electron may be responsible for the action of ECD.[21] In a similar MS/MS fragmentation technique called electron-transfer dissociation, the electrons are transferred by collision between the analyte cations and reagent anions.[22][23][24]
Applications
Disulfide bond cleavage
ECD itself and combined with other MS is very useful for proteins and peptides containing multiple disulfide bonds. FTICR combined with ECD helps to recognize peptides containing disulfide bonds. ECD could also access important sequence information by activation of higher charged proteins. Moreover, disulfide bond cleavage takes place by ECD of multiply charge proteins or peptides produced by ESI.[25] Electron capture by these proteins releases H atom, captured by the disulfide bond to cause its dissociation.[26]
ECD with UV-based activation increases the top-down MS sequence coverage of disulfide bond containing proteins and cleaves a disulfide bond homolytically to produce two separated thiol radicals. This technique was observed with insulin and ribonuclease, which led them to cleave up to three disulfide bonds and increase the sequence coverage.[27]
Post-translational modifications
ECD-MS fragments can retain posttranslational modifications such as carboxylation, phosphorylation[28][29] and O-glycosylation.[6][30][31] ECD has the potential to do the top-down characterization of the major types of posttranslational modifications in proteins. It successfully cleaved 87 of 208 backbone bonds and provided the first direct characterization of a phosphoprotein, bovine β casein, simultaneously restricting the location of five phosphorylation sites. It has advantages over CAD to measure the degree of phosphorylation with a minimum number of losses of phosphates and for phosphopeptide/phosphoprotein mapping, which makes ECD a superior technique.[32]
Coupling of ECD with separation techniques
ECD has been coupled with capillary electrophoresis (CE) to gain insight into structural analysis of mixture of peptides and protein digest.[33] Micro-HPLC combined with ECD FTICR was used to analyze pepsin digest of cytochrome c.[34] Sequence tags were provided by analysis of a mixture of peptides and tryptic digest of bovine serum albumin when LC ECD FTICR MS was used.[35] Additionally, LC-ECD-MS/MS is provides longer sequence tags than LC-CID-MS/MS for identification of proteins.[14] ECD devices using radio frequency quadrupole ion trap are relevant for high-throughput proteomics.[36][8] Recently, Atmospheric pressure electron capture dissociation (AP-ECD) is emerging as a better technique because it can be implemented as a stand-alone ion-source device and doesn’t require any modification of the main instrument.[37][38]
Proteomics
Analysis of proteins can be done by either using top-down or bottom-up approach. However, better sequence coverage is provided by top-down analysis.[39] Combination of ECD with FTICR MS has resulted in popularity of this approach. It has also helped in determining the multiple modification sites in intact proteins.[40][41] Native electron capture dissociation (NECD) was used to study cytochrome c dimer[42] and has been recently used to elucidate iron-binding channels in horse spleen ferritin.[43]
Synthetic polymers
ECD studies of polyalkene glycols, polyamides, polyacrylates and polyesters are useful for understanding composition of polymer samples. It has become a powerful technique to analyze structural information about precursor ions during MS/MS for synthetic polymers. ECD's single bond cleavage tendency makes the interpretation of product ion scans simple and easy for polymer chemistry.[44]
References
- Zubarev, Roman A.; Kelleher, Neil L.; McLafferty, Fred W. (1998-04-01). "Electron Capture Dissociation of Multiply Charged Protein Cations. A Nonergodic Process". Journal of the American Chemical Society. 120 (13): 3265–3266. doi:10.1021/ja973478k. ISSN 0002-7863.
- McLafferty, Fred W.; Horn, David M.; Breuker, Kathrin; Ge, Ying; Lewis, Mark A.; Cerda, Blas; Zubarev, Roman A.; Carpenter, Barry K. (2001-03-01). "Electron capture dissociation of gaseous multiply charged ions by Fourier-transform ion cyclotron resonance". Journal of the American Society for Mass Spectrometry. 12 (3): 245–249. doi:10.1016/s1044-0305(00)00223-3. ISSN 1044-0305. PMID 11281599.
- Zubarev, Roman; Haselmann (2002). "Towards An Understanding of the Mechanism of Electron-Capture Dissociation: A Historical Perspective and Modern Ideas". European Journal of Mass Spectrometry. 8 (5): 337–349. doi:10.1255/ejms.517.
- Tsybin, Youri O.; Ramström, Margareta; Witt, Matthias; Baykut, Gökhan; Håkansson, Per (2004-07-01). "Peptide and protein characterization by high-rate electron capture dissociation Fourier transform ion cyclotron resonance mass spectrometry". Journal of Mass Spectrometry. 39 (7): 719–729. Bibcode:2004JMSp...39..719T. doi:10.1002/jms.658. ISSN 1096-9888. PMID 15282750.
- Zubarev, R. A.; Horn, D. M.; Fridriksson, E. K.; Kelleher, N. L.; Kruger, N. A.; Lewis, M. A.; Carpenter, B. K.; McLafferty, F. W. (2000-02-01). "Electron capture dissociation for structural characterization of multiply charged protein cations". Analytical Chemistry. 72 (3): 563–573. doi:10.1021/ac990811p. ISSN 0003-2700. PMID 10695143.
- Haselmann, Kim F.; Budnik, Bogdan A.; Olsen, Jesper V.; Nielsen, Michael L.; Reis, Celso A.; Clausen, Henrik; Johnsen, Anders H.; Zubarev, Roman A. (2001-07-01). "Advantages of External Accumulation for Electron Capture Dissociation in Fourier Transform Mass Spectrometry". Analytical Chemistry. 73 (13): 2998–3005. doi:10.1021/ac0015523. ISSN 0003-2700. PMID 11467546.
- Tsybin, Youri O.; Håkansson, Per; Budnik, Bogdan A.; Haselmann, Kim F.; Kjeldsen, Frank; Gorshkov, Michael; Zubarev, Roman A. (2001-10-15). "Improved low-energy electron injection systems for high rate electron capture dissociation in Fourier transform ion cyclotron resonance mass spectrometry". Rapid Communications in Mass Spectrometry. 15 (19): 1849–1854. Bibcode:2001RCMS...15.1849T. doi:10.1002/rcm.448. ISSN 1097-0231. PMID 11565103.
- Baba, Takashi; Campbell, J. Larry; Le Blanc, J. C. Yves; Hager, James W.; Thomson, Bruce A. (2015-01-06). "Electron Capture Dissociation in a Branched Radio-Frequency Ion Trap". Analytical Chemistry. 87 (1): 785–792. doi:10.1021/ac503773y. ISSN 0003-2700. PMID 25423608.
- Liu, H. & Håkansson, K. J Am Soc Mass Spectrom (2007) 18: 2007. doi:10.1016/j.jasms.2007.08.015; Haselmann and Schmidt, RCM 21:1003-1008, 2007; Cooper JASMS 16:1932-1940, 2005.
- Leach, Franklin E.; Wolff, Jeremy J.; Laremore, Tatiana N.; Linhardt, Robert J.; Amster, I. Jonathan (2008). "Evaluation of the experimental parameters which control electron detachment dissociation, and their effect on the fragmentation efficiency of glycosaminoglycan carbohydrates". International Journal of Mass Spectrometry. 276 (2–3): 110–115. Bibcode:2008IJMSp.276..110L. doi:10.1016/j.ijms.2008.05.017. PMC 2633944. PMID 19802340.
- McFarland M. A.; Marshall A. G.; Hendrickson C. L.; Nilsson C. L.; Fredman P.; Månsson J. E. (May 2005). "Structural characterization of the GM1 ganglioside by infrared multiphoton dissociation, electron capture dissociation, and electron detachment dissociation electrospray ionization FT-ICR MS/MS". J. Am. Soc. Mass Spectrom. 16 (5): 752–62. doi:10.1016/j.jasms.2005.02.001. PMID 15862776.
- Wolff J. J.; Laremore T. N.; Busch A. M.; Linhardt R. J.; Amster I. J. (June 2008). "Influence of charge state and sodium cationization on the electron detachment dissociation and infrared multiphoton dissociation of glycosaminoglycan oligosaccharides". J. Am. Soc. Mass Spectrom. 19 (6): 790–8. doi:10.1016/j.jasms.2008.03.010. PMC 2467392. PMID 18499037.
- Harrison A. G. (2009). "To b or not to b: the ongoing saga of peptide b ions". Mass Spectrom. Rev. 28 (4): 640–54. Bibcode:2009MSRv...28..640H. doi:10.1002/mas.20228. PMID 19338048.
- Creese, Andrew J.; Cooper, Helen J. (2007-05-01). "Liquid chromatography electron capture dissociation tandem mass spectrometry (LC-ECD-MS/MS) versus liquid chromatography collision-induced dissociation tandem mass spectrometry (LC-CID-MS/MS) for the identification of proteins". Journal of the American Society for Mass Spectrometry. 18 (5): 891–897. doi:10.1016/j.jasms.2007.01.008. ISSN 1044-0305. PMC 2572008. PMID 17350280.
- Cooper H. J.; Håkansson K.; Marshall A. G. (2005). "The role of electron capture dissociation in biomolecular analysis". Mass Spectrometry Reviews. 24 (2): 201–22. Bibcode:2005MSRv...24..201C. doi:10.1002/mas.20014. PMID 15389856.
- Baba et al., Anal. Chem., 76:4263–4266, 2004.
- Ding, Li; Brancia, Francesco L. (2006-03-01). "Electron Capture Dissociation in a Digital Ion Trap Mass Spectrometer". Analytical Chemistry. 78 (6): 1995–2000. doi:10.1021/ac0519007. ISSN 0003-2700. PMID 16536438.
- Deguchi, Kisaburo; Ito, Hiroki; Baba, Takashi; Hirabayashi, Atsumu; Nakagawa, Hiroaki; Fumoto, Masataka; Hinou, Hiroshi; Nishimura, Shin-Ichiro (2007-03-15). "Structural analysis of O-glycopeptides employing negative- and positive-ion multi-stage mass spectra obtained by collision-induced and electron-capture dissociations in linear ion trap time-of-flight mass spectrometry". Rapid Communications in Mass Spectrometry. 21 (5): 691–698. Bibcode:2007RCMS...21..691D. doi:10.1002/rcm.2885. ISSN 1097-0231. PMID 17279605.
- Syrstad E. A.; Turecek F. (2005). "Toward a general mechanism of electron capture dissociation". J. Am. Soc. Mass Spectrom. 16 (2): 208–24. doi:10.1016/j.jasms.2004.11.001. PMID 15694771.
- Savitski M. M.; Kjeldsen F.; Nielsen M. L.; Zubarev R. A. (2006). "Complementary sequence preferences of electron-capture dissociation and vibrational excitation in fragmentation of polypeptide polycations". Angew. Chem. Int. Ed. Engl. 45 (32): 5301–3. doi:10.1002/anie.200601240. PMID 16847865.
- Leymarie N.; Costello C. E.; OConnor P. B. (2003). "Electron Capture Dissociation Initiates a Free Radical Reaction Cascade". J. Am. Chem. Soc. 125 (29): 8949–8958. doi:10.1021/ja028831n. PMID 12862492.
- Coon, Joshua J.; Shabanowitz, Jeffrey; Hunt, Donald F.; Syka, John E. P. (2005-06-01). "Electron transfer dissociation of peptide anions". Journal of the American Society for Mass Spectrometry. 16 (6): 880–882. doi:10.1016/j.jasms.2005.01.015. ISSN 1044-0305. PMID 15907703.
- Zubarev RA, Zubarev AR, Savitski MM (2008). "Electron capture/transfer versus collisionally activated/induced dissociations: solo or duet?". J. Am. Soc. Mass Spectrom. 19 (6): 753–61. doi:10.1016/j.jasms.2008.03.007. PMID 18499036.
- Hamidane, Hisham Ben; Chiappe, Diego; Hartmer, Ralf; Vorobyev, Aleksey; Moniatte, Marc; Tsybin, Yury O. (2009). "Electron capture and transfer dissociation: Peptide structure analysis at different ion internal energy levels". Journal of the American Society for Mass Spectrometry. 20 (4): 567–575. doi:10.1016/j.jasms.2008.11.016. ISSN 1044-0305. PMID 19112028.
- Zubarev, Roman A.; Kruger, Nathan A.; Fridriksson, Einar K.; Lewis, Mark A.; Horn, David M.; Carpenter, Barry K.; McLafferty, Fred W. (1999-03-01). "Electron Capture Dissociation of Gaseous Multiply-Charged Proteins Is Favored at Disulfide Bonds and Other Sites of High Hydrogen Atom Affinity". Journal of the American Chemical Society. 121 (12): 2857–2862. doi:10.1021/ja981948k. ISSN 0002-7863.
- Dass, Chhabil (2001). Principles and practice of biological mass spectrometry. New York. ISBN 978-0471330530.
- Wongkongkathep, Piriya; Li, Huilin; Zhang, Xing; Loo, Rachel R. Ogorzalek; Julian, Ryan R.; Loo, Joseph A. (2015). "Enhancing protein disulfide bond cleavage by UV excitation and electron capture dissociation for top-down mass spectrometry". International Journal of Mass Spectrometry. 390: 137–145. Bibcode:2015IJMSp.390..137W. doi:10.1016/j.ijms.2015.07.008. PMC 4669582. PMID 26644781.
- Creese, Andrew J.; Cooper, Helen J. (2008-09-01). "The effect of phosphorylation on the electron capture dissociation of peptide ions". Journal of the American Society for Mass Spectrometry. 19 (9): 1263–1274. doi:10.1016/j.jasms.2008.05.015. ISSN 1044-0305. PMC 2570175. PMID 18585055.
- Woodling, Kellie A.; Eyler, John R.; Tsybin, Yury O.; Nilsson, Carol L.; Marshall, Alan G.; Edison, Arthur S.; Al-Naggar, Iman M.; Bubb, Michael R. (2007-12-01). "Identification of single and double sites of phosphorylation by ECD FT-ICR/MS in peptides related to the phosphorylation site domain of the myristoylated alanine-rich c kinase protein". Journal of the American Society for Mass Spectrometry. 18 (12): 2137–2145. doi:10.1016/j.jasms.2007.09.010. ISSN 1044-0305. PMID 17962038.
- Mirgorodskaya, E.; Roepstorff, P.; Zubarev, R. A. (1999-10-01). "Localization of O-Glycosylation Sites in Peptides by Electron Capture Dissociation in a Fourier Transform Mass Spectrometer". Analytical Chemistry. 71 (20): 4431–4436. doi:10.1021/ac990578v. ISSN 0003-2700. PMID 10546526.
- Renfrow, Matthew B.; Cooper, Helen J.; Tomana, Milan; Kulhavy, Rose; Hiki, Yoshiyuki; Toma, Kazunori; Emmett, Mark R.; Mestecky, Jiri; Marshall, Alan G. (2005-05-13). "Determination of Aberrant O-Glycosylation in the IgA1 Hinge Region by Electron Capture Dissociation Fourier Transform-Ion Cyclotron Resonance Mass Spectrometry". Journal of Biological Chemistry. 280 (19): 19136–19145. doi:10.1074/jbc.m411368200. ISSN 0021-9258. PMID 15728186.
- Shi, Stone D.-H.; Hemling, Mark E.; Carr, Steven A.; Horn, David M.; Lindh, Ingemar; McLafferty, Fred W. (2001-01-01). "Phosphopeptide/Phosphoprotein Mapping by Electron Capture Dissociation Mass Spectrometry". Analytical Chemistry. 73 (1): 19–22. doi:10.1021/ac000703z. ISSN 0003-2700. PMID 11195502.
- Tsybin, Håkansson, Wetterhall, Markides, Bergquist (2017). "Capillary Electrophoresis and Electron Capture Dissociation Fourier Transform Ion Cyclotron Resonance Mass Spectrometry for Peptide Mixture and Protein Digest Analysis". European Journal of Mass Spectrometry. 8 (5): 389–395. doi:10.1255/ejms.514.CS1 maint: multiple names: authors list (link)
- Davidson, Walter; Frego, Lee (2002-05-30). "Micro-high-performance liquid chromatography/Fourier transform mass spectrometry with electron-capture dissociation for the analysis of protein enzymatic digests". Rapid Communications in Mass Spectrometry. 16 (10): 993–998. Bibcode:2002RCMS...16..993D. doi:10.1002/rcm.666. ISSN 1097-0231. PMID 11968133.
- Palmblad, Magnus; Tsybin, Youri O.; Ramström, Margareta; Bergquist, Jonas; Håkansson, Per (2002-05-30). "Liquid chromatography and electron-capture dissociation in Fourier transform ion cyclotron resonance mass spectrometry". Rapid Communications in Mass Spectrometry. 16 (10): 988–992. Bibcode:2002RCMS...16..988P. doi:10.1002/rcm.667. ISSN 1097-0231. PMID 11968132.
- Satake, Hiroyuki; Hasegawa, Hideki; Hirabayashi, Atsumu; Hashimoto, Yuichiro; Baba, Takashi; Masuda, Katsuyoshi (2007-11-01). "Fast Multiple Electron Capture Dissociation in a Linear Radio Frequency Quadrupole Ion Trap". Analytical Chemistry. 79 (22): 8755–8761. doi:10.1021/ac071462z. ISSN 0003-2700. PMID 17902701.
- Robb, Damon B.; Rogalski, Jason C.; Kast, Juergen; Blades, Michael W. (2011-10-01). "A New Ion Source and Procedures for Atmospheric Pressure-Electron Capture Dissociation of Peptides". Journal of the American Society for Mass Spectrometry. 22 (10): 1699–706. Bibcode:2011JASMS..22.1699R. doi:10.1007/s13361-011-0202-0. ISSN 1044-0305. PMID 21952883.
- Robb, Damon B.; Rogalski, Jason C.; Kast, Juergen; Blades, Michael W. (2012-05-01). "Liquid Chromatography–Atmospheric Pressure Electron Capture Dissociation Mass Spectrometry for the Structural Analysis of Peptides and Proteins". Analytical Chemistry. 84 (9): 4221–4226. doi:10.1021/ac300648g. ISSN 0003-2700. PMID 22494041.
- Kelleher, Neil L.; Lin, Hong Y.; Valaskovic, Gary A.; Aaserud, David J.; Fridriksson, Einar K.; McLafferty, Fred W. (1999-02-01). "Top Down versus Bottom Up Protein Characterization by Tandem High-Resolution Mass Spectrometry". Journal of the American Chemical Society. 121 (4): 806–812. doi:10.1021/ja973655h. ISSN 0002-7863.
- Chalmers, Michael J.; Håkansson, Kristina; Johnson, Robert; Smith, Richard; Shen, Jianwei; Emmett, Mark R.; Marshall, Alan G. (2004-04-01). "Protein kinase A phosphorylation characterized by tandem Fourier transform ion cyclotron resonance mass spectrometry". Proteomics. 4 (4): 970–981. doi:10.1002/pmic.200300650. ISSN 1615-9861. PMID 15048979.
- Ge, Ying; Lawhorn, Brian G.; ElNaggar, Mariam; Strauss, Erick; Park, Joo-Heon; Begley, Tadhg P.; McLafferty, Fred W. (2002-01-01). "Top Down Characterization of Larger Proteins (45 kDa) by Electron Capture Dissociation Mass Spectrometry". Journal of the American Chemical Society. 124 (4): 672–678. doi:10.1021/ja011335z. ISSN 0002-7863. PMID 11804498.
- Breuker, Kathrin; McLafferty, Fred W. (2003-10-20). "Native Electron Capture Dissociation for the Structural Characterization of Noncovalent Interactions in Native Cytochromec". Angewandte Chemie International Edition. 42 (40): 4900–4904. doi:10.1002/anie.200351705. ISSN 1521-3773. PMID 14579433.
- Skinner, Owen S.; McAnally, Michael O.; Van Duyne, Richard P.; Schatz, George C.; Breuker, Kathrin; Compton, Philip D.; Kelleher, Neil L. (2017-10-17). "Native Electron Capture Dissociation Maps to Iron-Binding Channels in Horse Spleen Ferritin". Analytical Chemistry. 89 (20): 10711–10716. doi:10.1021/acs.analchem.7b01581. ISSN 0003-2700. PMC 5647560. PMID 28938074.
- Hart-Smith, Gene (2014). "A review of electron-capture and electron-transfer dissociation tandem mass spectrometry in polymer chemistry". Analytica Chimica Acta. 808: 44–55. doi:10.1016/j.aca.2013.09.033. PMID 24370092.