Peptide Modifications
- N-terminal acetylation & C-terminal amidation
These modifications may avoid unnatural charges at the peptide terminals and make the peptide more closely mimic the charge state in the native protein. In addition, it may make the peptides more stable toward degradation resulting from exopeptidases. - N-terminal modification such as fatty acids, formylation and myristoylation, etc
- Peptides containing unusual amino acids
- - D-amino acids
- - L-β-homo amino acids
- - D-β-homo amino acids
- - N-methylated amino acids
- - Other specially modified amino acid derivatives
- Phosphorylation - on Ser, Thr and Tyr
Phosphopeptides can assist in the investigation of the influences of phosphorylation on peptides and protein structure and in the understanding of regulatory processes mediated by protein kinases. - Multiple Antigenic Peptides
This system is based on a small immunologically inert core molecule of radially branching lysine dendrites onto which a number of peptide antigens are anchored. This approach eliminates the need to conjugate the antigen to a protein carrier. - Peptide cyclization
- - Cys-Cys disulfide bridge
- - Peptide Macrolactam
- - Peptide thioether
- - Parallel and anti-parallel cyclic dimers
- Peptide biotinylation
The 6-carbon ε-aminocaproic is the most popular spacer; however, other spacers can also used upon requirement. The biotinylation site can be at N-terminal, internal and C-terminal - Peptide fluorescent labeling
Different fluorescent dyes (FITC, FAM etc.) and fluorophore/quencher pair can be added to the peptide N- and C-termini. For N-term labeling, ε-aminocaproic is generally inserted between the fluorophore and the peptide. - Peptide PEGylation
Peptide PEGylation can increase the peptide solubility, may also increased the bioavailability and the in vivo stability, decrease the immunogenicity.