Activation of protonated peptides and molecular ions of small molecules using heated filaments in Fourier-transform ion cyclotron resonance mass spectrometry

Wong, Richard L.; Robinson, Eric; Williams, Evan R.

doi:10.1016/j.ijms.2003.12.003

Cited by 9 publications

(8 citation statements)

References 38 publications

(77 reference statements)

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“…A similar observation was also made in the other publications in which heated tungsten wires were employed in order to thermally dissociate the ions in the ICR cell. For example, Williams and coworkers showed that they could “estimate the effective temperature of the ion to be ∼426 K (153°C) based on Arrhenius values obtained from the previous blackbody infrared radiation dissociation experiments, which corresponded to a ∼120°C increase from the slightly heated 35°C ion cell” 12…”

Section: Resultsmentioning

confidence: 99%

“…Molecular ions stored in an ion cyclotron resonance (ICR) cell can absorb this radiation emitted from the heated cathode. As a result, the internal temperature of a biomolecule in the ICR cell is expected to increase via co‐vibrational excitations of many vibrational modes existing in a large molecular ion (thermal activation effect) 12. This heating effect is anticipated to become more significant when the cathode is located just outside an ICR cell, which is often the case because of the ease of installation and the maximized overlap with the ion cloud in the cell.…”

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confidence: 99%

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Evaluation of the internal temperatures of an 8.6 kDa protein cation exposed to a hot dispenser cathode employed in electron capture dissociation mass spectrometry

Yim

Kim

Ahn

et al. 2006

Rapid Comm Mass Spectrometry

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The 'effective' internal temperature of an 8.6 kDa ubiquitin cation was estimated under electron capture dissociation (ECD) conditions, in which a dispenser cathode electron source was mounted just outside an ion cyclotron resonance (ICR) cell, i.e., axially displaced at a distance less than 1 cm from the rear trap plate of the ICR cell. In this ECD configuration, thermal activation of the molecular ions stored in the ICR cell was anticipated since the heated dispenser cathode (T(cathode surface) > 1000 degrees C) emitted a large amount of (both visible and infrared) radiation as well as electrons. An evaluation of the internal temperature of ubiquitin 6+ and 7+ cations was made by comparing our ECD fragmentation patterns with those obtained by McLafferty et al. (J. Am. Chem. Soc. 2002; 124: 6407) as a function of the ion temperature. In McLafferty's configuration, the heating (or thermal activation) effect of their filament source was minimal since the filament was displaced by a distance as far as 70 cm from their ICR cell. A careful comparison reveals that the fragmentation patterns obtained in this work are very similar to those previously measured at T approximately 125 degrees C. In terms of sequence coverage, our ECD configuration provides better results, and in particular without the aid of any other simultaneous activation method, such as thermal heating, infrared multiphoton irradiation, or collisional activation, except for the visible and infrared radiation from the heated cathode.

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Section: Resultsmentioning

confidence: 99%

mentioning

confidence: 99%

Evaluation of the internal temperatures of an 8.6 kDa protein cation exposed to a hot dispenser cathode employed in electron capture dissociation mass spectrometry

Yim

Kim

Ahn

et al. 2006

Rapid Comm Mass Spectrometry

View full text Add to dashboard Cite

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“…This high temperature may cause undesired heating of precursor ions that can result in thermally induced dissociation [32,33]. In order to minimize this problem, it would be desirable to perform EDD at lower cathode heating current.…”

Section: Can We Perform Edd At Lower Cathode Temperature?mentioning

confidence: 99%

Characterization and optimization of electron detachment dissociation Fourier transform ion cyclotron resonance mass spectrometry

Yang

Håkansson

2008

International Journal of Mass Spectrometry

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“…However, heated metal filaments, similar to the hollow electron emitter used as the electron source for ECD, have previously been used to dissociate ions trapped in FT/ICR cells [61][62][63]. Compared with the heated metal filaments, which raised the internal energy of protonated leucine enkephalin by 50 °C [63], the heated cathode electron emitter deposits significantly less power (30% less) with a smaller surface area (40% less) and is significantly farther from the ion cloud (180% farther). Because the energy deposited into ions by radiation decreases rapidly with increasing distance between the energy source and the ions [63], the internal energy rise due to absorption of IR photons produced by the heated cathode is expected to be minimal.…”

Section: Cleavage Residue Difference In Normalized Intensitymentioning

confidence: 99%

The role of conformation on electron capture dissociation of ubiquitin

Robinson

Leib

Williams

2006

J. Am. Soc. Mass Spectrom.

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Effects of protein conformation on electron capture dissociation (ECD) were investigated using high-field asymmetric waveform ion mobility spectrometry (FAIMS) and Fourier-transform ion cyclotron resonance mass spectrometry. Under the conditions of these experiments, the electron capture efficiency of ubiquitin 6ϩ formed from three different solution compositions differs significantly, ranging from 51 Ϯ 7% for ions formed from an acidified water/methanol solution to 88 Ϯ 2% for ions formed from a buffered aqueous solution. This result clearly indicates that these protein ions retain a memory of their solution-phase structure and that conformational differences can be probed in an ECD experiment. Multiple conformers for the 7ϩ and 8ϩ charge states of ubiquitin were separated using FAIMS. ECD spectra of conformer selected ions of the same charge states differ both in electron capture efficiency and in the fragment ion intensities. Conformers of a given charge state that have smaller collisional cross sections can have either a larger or smaller electron capture efficiency. A greater electron capture efficiency was observed for ubiquitin 6ϩ that has the same collisional cross section as one ubiquitin 7ϩ conformer, despite the lower charge state. These results indicate that the shape of the molecule can have a greater effect on electron capture efficiency than either collisional cross section or charge state alone. The cleavage locations of different conformers of a given charge state were the same indicating that the presence of different conformers in the gas phase is not due to difference in where charges are located, but rather reflect conformational differences most likely originating from solution. Small neutral losses observed from the singly-and doubly-reduced ubiquitin 6ϩ do not show a temperature dependence to their formation, consistent with these ions being formed by nonergodic processes. [7][8][9] can be obtained. Methods based on this electron capture process appear promising for bottom up and top down approaches in proteomics due to the high information content obtained in the fragmentation spectra [10 -12]. Sequence coverage of over 90% has been reported for small proteins [13]. Several methods for implementing electron capture that use different electron sources have been reported: electron capture dissociation (ECD) with free electrons from a heated filament or cathode [1-3], electron-transfer dissociation utilizing anion reagents [14 -17], electron removal by electron impact followed by capture of a free electron in electronic excitation dissociation [18], and collisionally induced electron-transfer from neutral atoms or molecules [19,20].A consequence of the extensive fragmentation produced by ECD is that the precursor ion population can be fractionated into potentially hundreds or even thousands of fragment ions. Thus, the intensity of any particular fragment ion is typically small compared with the original precursor ion intensity [1]. High electron capture and fragmentation efficiency are cr...

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Activation of protonated peptides and molecular ions of small molecules using heated filaments in Fourier-transform ion cyclotron resonance mass spectrometry

Cited by 9 publications

References 38 publications

Evaluation of the internal temperatures of an 8.6 kDa protein cation exposed to a hot dispenser cathode employed in electron capture dissociation mass spectrometry

Evaluation of the internal temperatures of an 8.6 kDa protein cation exposed to a hot dispenser cathode employed in electron capture dissociation mass spectrometry

Characterization and optimization of electron detachment dissociation Fourier transform ion cyclotron resonance mass spectrometry

The role of conformation on electron capture dissociation of ubiquitin

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