| abstract |
The present invention provides a method and compositions for synthesizing an oligopeptide or polypeptide by convergent assembly of a plurality of pairs of oligopeptides in chemical ligation reactions. An important aspect of the present invention is an oligopeptide having a C-terminal disulfide-protected carboxythioester group that can be deprotected to spontaneously generate a free C-terminal thioester moiety. This allows a single precursor to participate in a succession of chemical ligation reactions, thereby making the convergent synthesis approach possible. The present invention is useful in methods for chemical synthesis of oligopeptides, polypeptides and proteins, and improves the efficiency of native chemical ligation reactions, particularly where four or more peptide fragments are used to assemble an oligopeptide, polypeptide or protein product. |