Peptides exist in every living cell and possess various biochemical activities. They exist in the form of enzymes, hormones, antibiotics, and receptors. They constitute the main components of muscles, hair, and skin. Therefore, scientists are very interested in synthesizing peptides in the laboratory. This interest has developed into an important synthetic field called peptide synthesis. There are four main objectives in this field:
1. Verify the structure of natural peptides through degradation technology.
2. Study the relationship between the structure and activity of bioactive proteins and peptides, and establish their molecular mechanisms.
3. Synthesize medically important peptides such as hormones and vaccines.
4. Develop new peptide based immunogens.
The basic principle of this technology is to incorporate Na amino acids into peptides of any desired sequence, with one end of the sequence still attached to the solid-phase carrier matrix. The synthesis of peptides usually adopts a stepwise method, and all soluble reagents can be removed from the peptide solid phase carrier matrix by filtration and washed off at the end of each coupling step. After obtaining the required amino acid sequence, the peptide can be removed from the polymer carrier.
The general scheme for solid-phase peptide synthesis is shown in Figure 1. Solid phase carrier is a synthetic polymer with reactive groups (such as - OH). These functional groups are prone to react with the carboxyl groups of sodium protected amino acids, thereby covalently binding them to the polymer. Then the amino protecting group (X) can be removed, and the second sodium protected amino acid can be coupled to the connected amino acid. Repeat these steps until the desired sequence is obtained. At the end of synthesis, different reagents are used to cleave the bond between the C-terminal amino acid and the polymer carrier; Then the peptide enters the solution and can be obtained from the solution.
