Recent developments in peptide ligation independent of amino acid side-chain functional group

Chemical synthesis of peptides and proteins has evolved into an indispensable tool for chemical biology. Peptide ligation is a straightforward technique for joining two short peptide fragments together via a native peptide bond to afford a larger natural peptide or protein. However, the junction sites are limited to several specific amino acids because most peptide ligations involve participation of the side-chain functional groups of the junction-site amino acids. To overcome such intrinsic limitations, "general"peptide ligations which do not rely on the side-chain functional group have been developed. This review summarized the recent developments in peptide ligations that are independent of side-chain functional group of ligation-junction-site amino acid.