Many structural modifications of peptides guided by rational design and molecular modeling have been established to develop novel synthetic approaches.
Our group is presently focusing on the first point and designing novel modifications of peptide-based vaccines able to induce regulatory cells.
Artificial modifications of peptides (carbamidomethylation of cysteines and partial oxidation of methionines) were considered.
The artificial modifications of peptides (carbamidomethylation of cysteines and partial oxidation of methionines) were also considered.
Formalin-fixation induces diverse chemical modifications of peptides, including the formation of methylol groups, Schiff bases, and methylene bridges [ 15].
However, structural modifications of peptides often reduce their binding affinity and/or internalisation kinetics and, thus, tracer uptake.
The electron-based fragmentation methods are believed to be extremely selective with respect to peptide bonds [ 34], and consequently, the ECD should not influence the modifications of peptides.
However, in vivo applications require technically challenging chemical modifications of peptides, and while mouse xenograft models of virally-infected BH3 domain-expressing tumor cells can be used, this does not allow evaluation of effects of the ligand on normal tissues.
The first modification of peptide with mass 1705.7642 Da is an N-terminal loss of NH3 with −17.0265 Da and cyclization of glutamine (Q) [17], while the second modification of peptide with mass 1721.7544 Da is an extra oxidation of methionine (M), which leads to an increase of the mass by 15.999 Da (net change 15.999 17.0265 ≈ −1 Da).
For the global proteomic dataset, carbamidomethylation of cysteine and iTRAQ 4-plex modification of peptide N-termini were set as fixed modifications, and oxidation of methionine and iTRAQ 4-plex modification of Lys were set as variable modifications.
