Polypeptide is a kind of biologically active substance related to various cell functions in the organism. Its molecular structure is between amino acids and proteins. It is a compound composed of multiple amino acids combined by peptide bonds in a certain sequence. Polypeptide is a general term for biologically active substances related to various cell functions in organisms, and is often used in functional analysis, antibody research, especially drug development and other fields.
Peptide synthesis is a solid-phase synthesis sequence generally from the N-terminal (amino-terminal) to the C-terminal (carboxy-terminal).
The solid-phase peptide synthesis method has become an effective method for peptide synthesis due to its convenient and rapid synthesis, and has brought a revolution in peptide organic synthesis, and has become an independent discipline-solid-phase organic synthesis, solid-phase synthesis The invention also promotes the automation of peptide synthesis. The world’s first true peptide synthesizer appeared in the early 1980s.
Based on the repeated addition of a single N-α protected amino acid to the growing amino component, the synthesis proceeds step by step, usually starting from the C-terminal amino acid of the synthetic chain, and then connecting the individual amino acids by using DCC, mixed carbon anhydride, or N- The carboxy anhydride method is implemented. The Carbodiimide method involves the use of DCC as a linker to link N- and C-protected amino acids. Importantly, this linking reagent promotes the shrinkage between the carbon group of the N-protected amino acid and the free amino group of the C-protected amino acid to form a peptide chain and produce by-products.
However, this method causes side reactions of racemization or is affected in the presence of strong bases. Fortunately, these side reactions can be minimized, but not completely eliminated. The method is to add a linking catalyst. In addition, this method can also be used to synthesize active ester derivatives of N-protected amino acids. The active ester produced in sequence will spontaneously react with any other C-protected amino acid or peptide to form a new peptide.