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Synthesis of Bioactive Peptides for Pharmaceutical Applications
Published in Peter Grunwald, Pharmaceutical Biocatalysis, 2019
Jaison Jeevanandam, Ashish Kumar Solanki, Shailza Sharma, Prabir Kumar Kulabhusan, Sapna Pahil, Michael K. Danquah
Smaller peptide chains are ligated to form longer peptides through chemical and enzyme-mediated technologies. This peptide fragment linking process is called “fragment condensation.” However, there are limitations associated with this technique, some of which are the racemization and formation of other interfering by-products. Development in the field of peptide ligation leads to a unique method called native chemical ligation (NCL). This method leads to the establishment of a native bond between Cysteine from N-terminal and thioester from C-terminal with two segments of unprotected peptides. After an initial exchange of chemo-selective thiol-thioester, the reaction progresses to form the desired peptide bond by an irreversible intramolecular S,N-acyl shift (Dawson et al., 1994).
Polyaminoacid-based nanocarriers: a review of the latest candidates for oral drug delivery
Published in Expert Opinion on Drug Delivery, 2020
Sandra Robla, Maria José Alonso, Noemi S. Csaba
Among the synthesis strategies, solid-phase peptide synthesis (SPPS) is the most common technique for the synthesis of short peptides with controlled composition and length [25]. This method is based on the anchoring of an amino acid to a solid matrix and the subsequent addition of successive amino acids that bind to the initial unit, producing a lengthening polyaminoacid or peptide chain [26]. Another synthesis method uses reactive derivatives of amino acids (NCAs: amino acid N-carboxyanhydrides), where polypeptides or polypeptide-based synthesis are initiated by primary amines or alkoxide anions [27]. N-carboxyanhydride ring-opening polymerization (NCA-ROP) has permitted the production of high molecular weight homopolyaminoacids, as well as their functionalization with high reproducibility and minimal side product formation. Native chemical ligation (NCL) is based on a reaction between an unprotected peptide-thioester with another unprotected peptide containing an N-terminal cysteine in aqueous solution, producing a peptidic bond between the terminal cysteine of one peptide with the other [28]. Another method for synthesizing polypeptides is based on the chemo-enzymatic polymerization of amino acid monomers by aminolytic reaction using proteases, providing a green and clean chemical reaction with high yield in aqueous medium and mild conditions [29].