Does double electron capture lead to the formation of biradicals? An ECD-SORI-CID study on lacticin 481

Kleinnijenhuis, Anne J.; Heck, Albert J. R.; Duursma, Marc C.; Heeren, Ron M. A.

doi:10.1016/j.jasms.2005.05.010

Cited by 15 publications

(13 citation statements)

References 34 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The remaining 40% of the CRS population has an apparently lower rate of reaction with O 2 . This may be the result of several possible factors: the radical is located on a residue that is sterically hindered to O 2 ; the radical site is less reactive given its position/location (i.e., a nitrogen-centered radical S species could undergo radical-radical recombination to form a new chemical bond, thereby losing the ion's radical reactivity [12]. In case of melittin, this recombination rate is 100% and no radical reactivity is observed (i.e., no +O 2 reactions detected) ( Figure ESM-2).…”

Section: +mentioning

confidence: 99%

“…Kleinnijenhuis and coworkers [12] raised such a question in their study of doubly charge reduced lantibiotic peptides. They postulated that either B…the induced radical sites could recombine to form a new twoelectron pair, or they will not recombine and two fixed or mobile radical sites will remain present in the ion.^Based upon collision-induced dissociation of the triply protonated lanticin peptide and a CR 2 S form, they concluded that the radicals had recombined to form a new bond.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Capturing Polyradical Protein Cations after an Electron Capture Event: Evidence for their Stable Distonic Structures in the Gas Phase

Baba

Campbell

2015

J. Am. Soc. Mass Spectrom.

View full text Add to dashboard Cite

Abstract. We report on the formation and Bcapture^of polyradical protein cations after an electron capture event. Performed in a unique electroncapture dissociation (ECD) instrument, these experiments can generate reduced forms of multiply protonated proteins by sequential charge reduction using electrons with~1 eV. The true structures of these possible polyradicals is considered: Do the introduced unpaired electrons recombine quickly to form a new two-electron bond, or do these unpaired electrons exist as radical sites with appropriate chemical reactivity? Using an established chemical probe-radical quenching with molecular oxygen-we demonstrate that these charge-reduced protein cations are indeed polyradicals that form adducts with up to three molecules of oxygen (i.e., tri-radical protein cations) that are stable for at least 100 ms.

show abstract

Section: +mentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Capturing Polyradical Protein Cations after an Electron Capture Event: Evidence for their Stable Distonic Structures in the Gas Phase

Baba

Campbell

2015

J. Am. Soc. Mass Spectrom.

View full text Add to dashboard Cite

show abstract

“…Formation of biradicals has been previously discussed in electron capture dissociation of the lantibiotic lacticin 481 [45]. Formation of abundant non-dissociative species formed by single and double electron capture was observed.…”

Section: Ecd Of the Even [M + 2h] 2+ And Odd [M + H] 2+mentioning

confidence: 75%

“…Based on these reports [45,46], we reason that radical recombination, leading to a formation of a new bond, is very likely to occur following electron capture by the hydrogendeficient species. The Cornell mechanism [9,27,28,33] proposed electron capture to a protonation site to form a hypervalent radical from which a hydrogen atom can be released.…”

Section: Ecd Of the Even [M + 2h] 2+ And Odd [M + H] 2+mentioning

confidence: 91%

“…The authors suggested that species resulting from double electron capture can either exhibit a structure containing two separate radical sites or the two unpaired electrons recombine to form a new bond. SORI-CID of these double electron capture species revealed that recombination of the two radical sites is the dominant pathway, whereas a small part of the population of these double electron capture species exist as biradical ions containing two separate radical sites [45].…”

Section: Ecd Of the Even [M + 2h] 2+ And Odd [M + H] 2+mentioning

confidence: 99%

See 1 more Smart Citation

Electron Capture Dissociation of Hydrogen-Deficient Peptide Radical Cations

Kalli

Hess

2012

J. Am. Soc. Mass Spectrom.

View full text Add to dashboard Cite

Hydrogen-deficient peptide radical cations exhibit fascinating gas phase chemistry, which is governed by radical driven dissociation and, in many cases, by a combination of radical and charge driven fragmentation. Here we examine electron capture dissociation (ECD) of doubly, • precursor ions resulted in efficient electron capture by the hydrogen-deficient species. However, the intensities of c-and z-type product ions were reduced, compared with those observed for the even electron species, indicating suppression of N-C α backbone bond cleavages. We postulate that radical recombination occurs after the initial electron capture event leading to a stable even electron intermediate, which does not trigger N-C α bond dissociations. Although the intensities of c-and z-type product ions were reduced, the number of backbone bond cleavages remained largely unaffected between the ECD spectra of the even electron and hydrogen-deficient species. We hypothesize that a small ion population exist as a biradical, which can trigger N-C α bond cleavages. Alternatively, radical recombination and N-C α bond cleavages can be in competition, with radical recombination being the dominant pathway and N-C α cleavages occurring to a lesser degree. Formation of b-and y-type ions observed for two of the hydrogendeficient peptides examined is also discussed.

show abstract

Current literature in mass spectrometry

2006

J. Mass Spectrom.

View full text Add to dashboard Cite

The birdcage: The title anion, which contains two endohedral d10 metal atoms, is the second known ternary cluster anion comprising only metal atoms (see picture: Sn orange, Sn/Bi blue, Ni black). The K([2.2.2]crypt) salt was obtained upon reaction of the binary precursor [Sn2Bi2]2− with [Ni(cod)2] in ethylenediamine/toluene by a complicated fragmentation/re‐arrangement process. X‐ray diffraction and DFT calculations confirm the composition of the anion.

show abstract

Does double electron capture lead to the formation of biradicals? An ECD-SORI-CID study on lacticin 481

Cited by 15 publications

References 34 publications

Capturing Polyradical Protein Cations after an Electron Capture Event: Evidence for their Stable Distonic Structures in the Gas Phase

Capturing Polyradical Protein Cations after an Electron Capture Event: Evidence for their Stable Distonic Structures in the Gas Phase

Electron Capture Dissociation of Hydrogen-Deficient Peptide Radical Cations

Current literature in mass spectrometry

Contact Info

Product

Resources

About