Hydrogen Attachment/Abstraction Dissociation (HAD) of Gas-Phase Peptide Ions for Tandem Mass Spectrometry

Abstract

Dissociation of gas-phase peptide ions through interaction with low-energy hydrogen (H) radical (∼0.15 eV) was observed with a quadrupole ion trap mass spectrometry. The H radical generated by thermal dissociation of H2 molecules passing through a heated tungsten capillary (∼2000 °C) was injected into the ion trap containing target peptide ions. The fragmentation spectrum showed abundant c-/z- and a-/x-type ions, attributable to H attachment/abstraction to/from peptide ion. Because the low-energy neutral H radical initiated the fragmentation, the charge state of the precursor ion was maintained during the dissociation. As a result, precursor ions of any charge state, including singly charged positive and negative ions, could be analyzed for amino acid sequence. The sequence coverage exceeding 90% was obtained for both singly protonated and singly deprotonated substance P peptide. This mass spectrometry also preserved labile post-translational modification bonds. The modification sites of triply phosphorylated peptide (kinase domain of insulin receptor) were identified with the sequence coverage exceeding 80%.

Replacing H+by Na+or K+in phosphopeptide anions and cations prevents electron capture dissociation

“…S12 † ) further suggest that they are formed by intramolecular H˙ transfer to backbone amide oxygen, similar to the attachment of low-energy (∼0.15 eV) hydrogen atoms to backbone amide oxygen of even-electron peptide ions that was previously observed to initiate dissociation into c , z ˙ and c ˙, z fragments. 112 Moreover, intramolecular H˙ transfer to backbone amide oxygen is consistent with backbone cleavage at sites 5–10 (Fig. S12 † ), around the postulated protonation site at Q6, Q7, or Q8 in the (M – H + 4Na) 3+ ions.…”

Identification and Evaluation of Biomarkers for Niemann-Pick Disease Type C Based on Chemical Analysis Techniques

“…In summary, the results from Lyso-SM-509 were completely opposite to those of SPC, which was considered to be a structural analog [94]. To obtain further structural information, hydrogen abstraction/attachment dissociation (HAD)-MS/MS analysis was performed [106]. Unlike normal CID conditions, this method can cleave the double bonds in lipids [107].…”

Free radical‐initiated peptide sequencing (FRIPS)‐based cross‐linkers for improved peptide and protein structure analysis

“…Very recently, Takahashi et al introduced an alternative approach to open‐shell peptide chemistry, in which singly charged peptide ions, such as (peptide+H) + ions encounter reactive collisions with low‐energy hydrogen radicals in the gas phase of a quadrupole ion trap (hydrogen attachment/abstraction dissociation). The peptide precursor ions either attach a hydrogen atom forming [peptideH+H] + • species or lose a hydrogen atom to yield [peptideH−H] + • species.…”