Cyclic Peptide

Cyclic peptide is a polypeptide chain with a circular sequence of bonds (Fig. 1). Cyclic peptides are naturally-occurring molecules found in biological systems, including the well-known immunosuppressant cyclosporin A that is widely used in clinical practice worldwide to prevent graft rejection after organ transplantation. Cyclic peptides are highly soluble and exhibit high target affinity, selectivity and pharmacokinetic properties.

Cyclic-peptide ligands can be developed using either synthetic or genetic approaches. Using genetically encoded cyclic-peptide libraries in drug discovery has led to the identification of inhibitors of targets that are not well addressed by small molecules or macromolecule antibodies.

These compounds have the advantage of being easier to synthesize than small molecules and to screen for activity in cells. However, many challenges remain in translating hits identified in screens of cyclic-peptide libraries into clinical trials.

In addition, developing cyclic-peptides that can reach intracellular targets presents significant challenges. This is mainly because traditional calculated physical properties of chemical structures do not successfully predict cell membrane permeability. Nevertheless, various strategies, such as backbone N-methylation and stereochemical changes, have been used to develop molecular scaffolds with improved cell permeability without compromising biological activity.

Peptide cyclization is an important step in the development of peptide therapeutics, as it allows to achieve greater structural stability and target binding compared with straight-chain molecules. At GenScript, we provide a range of services for peptide cyclization, including head-to-tail cyclic-peptide library production, one disulfide bond cyclic-peptide, and split-intein-based cyclic peptide.


If you are interested in consuming peptides, it is imperative to consult a medical professional! If any action is taken as a result of this content, we cannot be held liable for any damages. Click on the icon to learn more about why a medical consultation is mandatory!

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