Abstract
Native chemical ligation(NCL) is a practical and efficient methodology for peptide/proteins synthesis. However, the rare presence of the cysteine residue (1.4% content in proteins) has limited the utility of NCL (most peptide pharmaceuticals rarely contain an internal cysteine). The previously work in our lab already developed a photocleavable auxiliary to modify Asp. Such building block has been used in NCL between dipeptides. The method of this job relied on Photocleavable-auxiliary-modified Asn/Gln to achieve NCL. Modified Asn/Gln can take place the role of Cys in NCL. Using solid-phase peptide synthesis (SPPS) to synthesis peptide sequences, then ligate peptide sequences by NCL. We use UV irradiation after NCL to obtain target peptide mild and rapidly. The objective of this job is use such method to achieve NCL between short-sequence peptides ligation and produce a valuable peptide/protein.