Negative electron transfer dissociation NETD

While most peptide dissociation is carried out in the positive ion mode, the negative ion mode is often better suited for acidic peptides, particularity those carrying acidic modifications (e.g., phosphorylations). There are a number of equivalent ion activation methods for peptide anions, involving ion-electron and ion-ion reactions, such as electron detachment dissociation (EDD) [49], negative electron transfer dissociation (NETD) [50, 51], and negative electron capture dissociation (nECD) [52]. 

A variation of EDD, termed negative electron transfer dissociation (NETD) employs fluoranthene, CieHio" , or Xe" ions instead of energetic electrons to induce radical cationic sites by charge transfer rather than by electron ionization [175]. NETD yields selective backbone cleavage at the Ca-C bonds, similar to EDD, but leaves the phosphorylation sites intact, thereby enabling the localization of posttranslational modifications (PTMs). 

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See also in sourсe #XX -- [ ]

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