The screening principle of peptide drug screening is to utilize the specific binding between peptide molecules in the peptide library and the target molecules, to screen out peptides with specific biological activities. Various methods of peptide drug screening are described below.
| Preparation Methods | Specification |
|---|---|
| Extraction Method | Currently, a significant portion of peptide drugs are extracted from plants and animals, such as insulin extracted from pig pancreas. The purity of peptides obtained by the extraction method is low, the content of peptides in organisms is very small, and animal pathogenic bacteria or viruses are easily introduced during the extraction process, thus limiting its application. |
| Chemical Synthesis Method | Liquid-phase synthesis of peptides is mainly carried out in solution, and there are two strategies: stepwise synthesis and fragment combination. These two strategies are often used in combination. Some short peptide fragments are first synthesized by stepwise synthesis. The peptide fragments obtained in the previous step are then joined to form the target peptide by fragmentation. |
The solid phase synthesis method involves immobilizing the N-terminus of an amino acid on an insoluble resin and then sequentially condensing the amino acid on this resin. The solid-phase method has become a common technique in peptide and protein synthesis. | |
| Recombinant Technology | Recombinant technology is used to form recombinant DNA expression vectors by constructing the gene sequences of polypeptides into vectors, and to express, extract, and purify the polypeptide molecules in prokaryotic or eukaryotic cells. This method is suitable for the preparation of target peptides consisting of more than 50 amino acids and is easier to obtain. |
| Enzyme Degradation Method | Since organisms contain a large number of proteins, and some active peptides may be certain sequences in proteins, it can also be cost-saving if more readily available proteins can be degraded into the desired peptide molecules. Enzymatic degradation methods often require the search for enzymes that catalyze catabolic reactions at specific structures, which can efficiently function at all the same structures in the protein. |
| CAT# | Product Name | CAS | Sequence |
|---|---|---|---|
| 10-101-291 | Bradykinin 1-7 | 23815-87-4 | Arg-Pro-Pro-Gly-Phe-Ser-Pro |
| 10-101-293 | GLP-1(7-36) Acetate | 1119517-19-9 | HAEGTFTSDVSSYLEGQAAKEFIAWLVKGR |
| 10-101-295 | Neurokinin A | 86933-74-6 | H-His-Lys-Thr-Asp-Ser-Phe-Val-Gly-Leu-Met-NH2 |
| 10-101-317 | Galanin, human | 119418-04-1 | GWTLNSAGYLLGPHAVGNHRSFSDKNGLTS |
| 10-101-319 | Orexin B human | 205640-91-1 | RSGPPGLQGRLQRLLQASGNHAAGILTM |
| 10-101-40 | Ornipressin | 3397-23-7 | Cys-Tyr-Phe-Gln-Asn-Cys-Pro-Orn-Gly-NH2(Cys1-Cys6) |
| 10-101-43 | Aviptadil Acetate | 40077-57-4 | HSDAVFTDNYTRLRKQMAVKKYLNSILN |
| 10-101-51 | Protirelin | 24305-27-9 | {pGlu}-His-Pro-NH2 |
| 10-101-53 | Eledoisin | 69-25-0 | H-Pyr-Pro-Ser-Lys-Asp-Ala-Phe-Ile-Gly-Leu-Met-NH2 |
| 10-101-66 | Kassinin | 63968-82-1 | H-Asp-Val-Pro-Lys-Ser-Asp-Gln-Phe-Val-Gly-Leu-Met-NH2 |
The primary methods are display technologies (phage, mRNA, yeast) which link genotype to phenotype, and synthetic library screening using arrays or one-bead-one-compound (OBOC) libraries.
Initial hits are chemically synthesized via solid-phase peptide synthesis (SPPS) at milligram scale, followed by purification using preparative reversed-phase HPLC to obtain material for validation.
Essential techniques include analytical HPLC for purity, mass spectrometry (MS) for identity and confirmation of modifications, and circular dichroism (CD) or NMR for structural analysis.
They are isolated through multi-step processes involving extraction, fractionation (e.g., size-exclusion, ion-exchange chromatography), and final purification by HPLC, guided by bioactivity assays.
LC-MS/MS is the cornerstone for peptide sequencing, identifying post-translational modifications, and quantifying peptides in complex mixtures like cell lysates or biological fluids.
For binding, SPR or BLI provide kinetics. For cellular activity, fluorometric/colorimetric assays, flow cytometry, or reporter gene assays are used. Detection often relies on labeled peptides or antibodies.
Scaling up requires transitioning to cost-effective solution-phase or hybrid synthesis, optimizing large-scale purification (e.g., counter-current chromatography), and implementing stringent process analytical technology (PAT) for quality control.
Stability is monitored through forced degradation studies (pH, temperature, oxidants) and long-term storage tests, using HPLC and MS to track degradation products and establish shelf-life.
