Dr. Mina Wang
1. Do you have a library of common cyclic peptides for peptide screening?
- We exclusively offer customized cyclic peptide libraries. If you require assistance with library design, our robust AI peptide design team is ready to help.
2. How does the prospect of using enzymes for peptide cyclization compare to chemical synthesis?
Advantages
- Enzyme peptide cyclization is more eco-friendly.
- In some situations, enzymes can cyclize short peptides and hydrophobic peptides, which are very difficult for chemical synthesis.
Disadvantages
- Peptide sequences must meet certain limitations. For example, SurE can be used for head-to-tail cyclization, but it strictly requires the pairing of terminal amino acids with opposite configurations (i.e., L-amino acid at N-terminus and D-amino acid at C-terminus) and a preference for bulky aromatic/aliphatic residues at the terminal positions.
- The purity of linear peptides usually needs to be high.
3. Do you have experience with epimerization during peptide synthesis? If so, what do you usually do?
Several strategies can be applied:
- Using conjugations with strong activity, like HATU;
- Reduce the reaction time;
- Lower the temperature at the activation step of amino acids.
4. How is the prospect of lasso peptides from an industrial perspective?
- Lasso peptides exhibit better stability than linear peptides and have been increasingly explored in the field of anti-infection. Many academic researchers have conducted extensive work in this area. However, in the industrial sector, the demand for lasso peptides is not significant. This might be attributed to the potentially high cost of synthesis and impurity studies.
5. Please comment on the stability and synthesis cost of cyclic, bicyclic, and tricyclic compounds.
- In my opinion, the stability of cyclic peptides has more to do with the cyclization strategies rather than the number of rings. For example, a thioether bond is much more stable than a disulfide bond, whether in vivo or in vitro, even when there are two disulfide bonds. Usually, the synthesis cost of these, arranged in increasing order, is cyclic peptide < bicyclic peptide < tricyclic peptide.
