Charge site mass spectra: conformation-sensitive components of the electron capture dissociation spectrum of a protein.

ABSTRACT: A conventional electron capture dissociation (ECD) spectrum of a protein is uniquely characteristic of the first dimension of its linear structure. This sequence information is indicated by summing the primary c (m+) and z (m+•) products of cleavage at each of its molecular ion's inter-residue bonds. For example, the ECD spectra of ubiquitin (M + nH)(n+) ions, n = 7-13, provide sequence characterization of 72 of its 75 cleavage sites from 1843 ions in seven c ((1-7)+) and eight z ((1-8)+•) spectra and their respective complements. Now we find that each of these c/z spectra is itself composed of "charge site (CS)" spectra, the c (m+) or z (m+•) products of electron capture at a specific protonated basic residue. This charge site has been H-bonded to multiple other residues, producing multip

SUBMITTER: Skinner OS 

PROVIDER: S-EPMC3730536 | biostudies-literature | 2013 Jun

REPOSITORIES: biostudies-literature