Unusual fragmentation of derivatized cysteine-containing peptides.

ABSTRACT:

Rationale

Modification of cysteines by aminoethylation results in side chains similar to those of lysine. Trypsin cleaves at this modified residue and this labeling method can facilitate the analysis of proteins, specifically antibodies. In this work, the ability to identify peptides containing aminoethylated cysteines is investigated through digestion, covalent labeling, and low-energy ion fragmentation.

Methods

A prototype antibody was reduced, aminoethylated, and digested with either Lys-N or Glu-C. The resulting peptides were amidinated with SMTA and analyzed by PSD in a MALDI-TOF/TOF mass spectrometer or by CID in an ESI ion trap/orbitrap mass spectrometer.

Results

PSD and CID fragmentation of peptides with an amidinated aminoethylated cysteine can produce an int

SUBMITTER: Degraan-Weber N 

PROVIDER: S-EPMC6430700 | biostudies-literature | 2018 Sep

REPOSITORIES: biostudies-literature