Peptide Drugs: Screening, Preparation, Isolation and Detection Methods
Peptide Drugs: Screening, Preparation, Isolation and Detection Methods
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How to Screen Peptide Drugs?
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.
- Phage Display Peptide Library
Phage display peptide library screening is a relatively mature screening method. Through 3 rounds of screening, more ideal strains can be obtained, and the sequence of small molecule peptides expressed by them can be inferred by DNA sequencing, and then the biological activities of small molecule peptides can be verified by directed synthesis. - Randomized Peptide Library
Randomized peptide libraries can be synthesized according to customer's requirements, usually with a short production cycle and large library capacity, the library capacity of a 10 amino acid peptide library can be up to 1012. Usually, there are two methods to synthesize randomized peptide libraries: split and mix and amino acid pre-mix. Peptide libraries obtained by the split and mix method have a more consistent content of different sequences and contain only one peptide per resin ball. - Antisense Peptide Library Screening
Antisense peptide libraries are biologically designed peptide libraries with a high screening success rate but require the identification of amino acid sequences in key regions of the target protein. Usually, the amino acid sequence of the critical region can be determined by comparison analysis using bioinformatic analysis software such as Clustal X. After the amino acid sequence is determined, the antisense peptide library is designed according to the Meker-Idlis (M-I) theory. At this point, antisense peptide libraries can be synthesized directly for peptide screening, or simulated by software (Discovery Studio) to obtain peptide libraries with smaller capacity.
Peptide Drug Preparation Methods
| 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. |
- High-Performance Liquid Chromatography (HPLC)
HPLC is the most commonly used method in drug quality analysis, which has the characteristics of sensitivity, accuracy, and rapidity. Peptides are made up of multiple amino acids connected by peptide bonds, which have a certain degree of hydrophobicity, and have a certain retention on reversed-phase columns, and can be effectively separated in reversed-phase HPLC, and nowadays, most of the analysis of substances related to peptide drugs is carried out by HPLC. - Capillary Electrophoresis
Capillary electrophoresis has the advantages of both high-pressure electrophoresis and liquid chromatography, and the separation mechanism is different from that of reversed-phase high-performance liquid chromatography (RP-HPLC) which is based on hydrophobicity, and there exist various separation modes, which has the features of fast analysis speed, high resolution, low sample dosage, simple operation, and low consumption. The separation is fast, high resolution, low sample volume, simple operation, and low consumption. - High-performance Liquid Chromatography - Mass Spectrometry (HPLC-MS)
When using liquid-liquid mass spectrometry for the analysis of peptide-related substances, it can give the primary or even multi-level mass spectrometry information of the impurity without obtaining the pure impurity, to obtain the molecular weight and sequence information of the impurity peptide, which can provide a basis for the peptide characterization and structural analysis. - High-performance Molecular Exclusion Chromatography
High-performance molecular chromatography is a liquid chromatographic technique for separation according to molecular size, which is commonly used for molecular weight determination of protein peptides, determination of biomacromolecule polymers and molecular weight distribution, and determination of macromolecular impurities in pharmaceuticals.
| 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 |
* Please kindly note that our products and services can only be used to support research purposes (Not for clinical use).
