Electron-capture dissociation

Electron-capture dissociation (ECD) is a method of fragmenting gas phase ions for tandem mass spectrometric analysis (structural elucidation). ECD involves the direct introduction of low energy electrons to trapped gas phase ions.[1][2] It was developed by Roman Zubarev and Neil Kelleher while in Fred McLafferty's lab at Cornell University.

Principles

Electron-capture dissociation typically involves a multiply protonated molecule M interacting with a free electron to form an odd-electron ion

[M + nH]^{n+} + e^- \to \bigg[ [M + nH]^{(n-1)+} \bigg]^* \to fragments.

Liberation of the electric potential energy results in fragmentation of the product ion.

ECD produces significantly different types of fragment ions (although primarily c- and z-type, b-ions have been identified in ECD[3]) than other MS/MS fragmentation methods such as electron-detachment dissociation (EDD) (primarily a and x type),[4][5][6][7][8] collision-induced dissociation (CID) (primarily b[9] 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 (and in EDD as well), fragments retain post-translational modifications such as phosphorylation[10][11][12] and O-glycosylation.[13][14] In ECD, unique fragments (and complementary to CID) are observed[15] and the ability to fragment whole macromolecules effectively has been promising. The low fragmentation efficiencies and other experimental difficulties, which are being studied,[16] have prevented widespread use. Although ECD is primarily used in Fourier transform ion cyclotron resonance mass spectrometry,[17] investigators have indicated that it has been successfully used in an ion trap mass spectrometer.[18][19][20]

ECD is a recently introduced MS/MS fragmentation technique and is still being investigated.[21][22] 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.[23]

In a similar MS/MS fragmentation technique called electron-transfer dissociation the electrons are transferred by collision between the analyte cations and reagent anions.[24][25][26][27]

See also

References

  1. Zubarev RA, Kelleher NL, McLafferty FW (1998). "Electron capture dissociation of multiply charged protein cations. A nonergodic process". J. Am. Chem. Soc. 120 (13): 3265–66. doi:10.1021/ja973478k.
  2. McLafferty, F.; Horn, D.M.; Breuker, K.; Ge, Y.; Lewis, M.A.; Cerda, B.; Zubarev, R.A.; Carpenter, B.K. (2001). "Electron capture dissociation of gaseous multiply charged ions by fourier-transform ion cyclotron resonance". Journal of the American Society for Mass Spectrometry 12 (3): 245–9. doi:10.1016/S1044-0305(00)00223-3. PMID 11281599.
  3. Liu and Hakansson, JASMS 18:2007-2013, 2007; Haselmann and Schmidt, RCM 21:1003-1008, 2007; Cooper JASMS 16:1932-1940, 2005
  4. Anusiewicz I, Jasionowski M, Skurski P, Simons J (December 2005). "Backbone and side-chain cleavages in electron detachment dissociation (EDD)". J Phys Chem A 109 (49): 11332–7. doi:10.1021/jp055018g. PMID 16331920.
  5. Leach FE, Wolff JJ, Laremore TN, Linhardt RJ, Amster IJ (October 2008). "EVALUATION OF THE EXPERIMENTAL PARAMETERS WHICH CONTROL ELECTRON DETACHMENT DISSOCIATION, AND THEIR EFFECT ON THE FRAGMENTATION EFFICIENCY OF GLYCOSAMINOGLYCAN CARBOHYDRATES". Int J Mass Spectrom 276 (2-3): 110–115. Bibcode:2008IJMSp.276..110L. doi:10.1016/j.ijms.2008.05.017. PMC 2633944. PMID 19802340.
  6. Kjeldsen F, Silivra OA, Ivonin IA, Haselmann KF, Gorshkov M, Zubarev RA (March 2005). "C alpha-C backbone fragmentation dominates in electron detachment dissociation of gas-phase polypeptide polyanions" (PDF). Chemistry 11 (6): 1803–12. doi:10.1002/chem.200400806. PMID 15672435.
  7. McFarland MA, Marshall AG, Hendrickson CL, Nilsson CL, Fredman P, Månsson JE (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.
  8. Wolff JJ, Laremore TN, Busch AM, Linhardt RJ, Amster IJ (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.
  9. Harrison AG (2009). "To b or not to b: the ongoing saga of peptide b ions". Mass Spectrom Rev 28 (4): 640–54. doi:10.1002/mas.20228. PMID 19338048.
  10. Creese & Cooper, JASMS 19:1263-1274, 2008
  11. Shi et al., Anal. Chem., 73:19-22, 2001
  12. Woodling et al., JASMS 18:2137-2145, 2007
  13. Mirgorodskaya et al., Anal. Chem. 71:4431-4436, 1999
  14. Renfrow et al., JBC 280:19136-19145, 2005
  15. Creese & Cooper JASMS 18:891-897, 2007
  16. Gorshkov et al., IJMS 234:131-136, 2004
  17. Cooper HJ, Håkansson K, Marshall AG (2005). "The role of electron capture dissociation in biomolecular analysis". Mass spectrometry reviews 24 (2): 201–22. doi:10.1002/mas.20014. PMID 15389856.
  18. Baba et al., Anal. Chem., 76:4263-4266, 2004
  19. Ding & Brancia, Anal. Chem. 78:1995-2000, 2006
  20. Deguchi et al., Rapid Communications in Mass Spectrometry 21: 691-698, 2007
  21. Syrstad EA, 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.
  22. Savitski MM, Kjeldsen F, Nielsen ML, Zubarev RA (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.
  23. Leymarie N, Costello CE, OConnor PB (2003). "Electron Capture Dissociation Initiates a Free Radical Reaction Cascade". J. Am. Chem. Soc. 125 (29): 8949–8958. doi:10.1021/ja028831n. PMID 12862492.
  24. Coon et al., JASMS 16:880-882, 2005
  25. Zubarev et al. (2008). JASMS 19: 753–761. Missing or empty |title= (help)
  26. Hamidane et al., JASMS 20:567-575, 2009
  27. Bakhtiar R, Guan Z (July 2006). "Electron capture dissociation mass spectrometry in characterization of peptides and proteins". Biotechnol. Lett. 28 (14): 1047–59. doi:10.1007/s10529-006-9065-z. PMID 16794768.