| abstract |
The invention is directed to methods and compositions for chemical ligation of components comprising a first component having a carboxythioester, and preferable an α-carboxythioester, moiety and a second component having an N-substituted, and preferably an Nα-substituted, 2 or 3 carbon chain alkyl or aryl thiol to give a ligation product having an N-substituted amide bond at the ligation site. The reactants of the invention are chemoselective, and the alkyl or aryl thiol moiety is removable from the ligation product. Removal of the alkyl or aryl thiol gives a native amide bond at the ligation site. The methods and compositions of the invention are particularly useful for ligation of peptides and polypeptides. The ligation system of the invention is applicable to a wide variety of molecules, and thus can be exploited to generate peptides, polypeptides and other amino acid containing polymers having a native amide bond at the ligation site. |