Chemical Protein Synthesis by Native Chemical Ligation and Variations Thereof

Abstract

For a long time, the total synthesis of proteins was considered as a “mission impossible” because of the tedious and complex synthetic steps and demanding purification processes. However, with the development of modern synthetic methodologies, many protein syntheses have now been reported. More importantly, through chemical synthesis, desired modifications can be installed to target proteins precisely, which is a major advantage over traditional bio‐synthesis approaches. This review summarizes the techniques developed for protein assembly, including native chemical ligation, Se‐mediated ligation, and a range of other ligation methods. A few synthetic examples, whereby synthetic proteins with desired modifications have been utilized for related biological research, are also included. We believe that chemical synthesis can provide alternative pathways to solve problems that have hitherto proved insurmountable by traditional biological approaches.

Modification of N-terminal α-amine of proteins via biomimetic ortho-quinone-mediated oxidation

“…6b). Both proteins were chemically synthesized via native chemical ligation 66,67 and refolded using cysteine/cystine redox 68 buffer on a > 30 mg scale (see Supplementary Note 4 for the syntheses of MIP-1β variants 29 and 30).…”

Facile Generation of Strained Peptidyl Thiolactones from Hydrazides and Its Application in Assembling MUC‐1 VNTR Oligomers†

“…Chemical synthesis could produce homogenous proteins that incorporate various unnatural amino acids and post‐translational modifications, thus becoming a powerful tool in studying protein structures and functions. [ 1 ] Considering the large size of most natural proteins and synthetic limitation of solid‐phase peptide synthesis (SPPS), [ 2 ] ligation of peptide segments is often required in chemical protein synthesis. [ 3 ] Native chemical ligation (NCL) is a widely used method (Scheme 1a), [ 4 ] which uses peptidyl thioesters and usually in combination with thiol additives such as 4‐mercaptophenylacetic acid (MPAA) to improve the reaction efficiency.…”

Use of a Removable Backbone Modification Strategy to Prevent Aspartimide Formation in the Synthesis of Asp Lactam Cyclic Peptides†

“…Lactam cyclic peptides have attracted widespread attention recently due to their structural rigidity, metabolic stability, and interesting biological activity; [ 1‐7 ] and the Asp‐based lactam cyclic peptide drug bremelanotide (Scheme 1), a highly potent synthetic analogue of α‐melanocyte‐stimulating hormone, was recently approved by FDA. [ 8 ] Asp‐based lactam cyclic peptides are usually synthesized by Fmoc solid‐phase synthesis (SPPS), [ 9‐15 ] which generally entails removal of the temporary protecting groups on the side chains of Asp and Lys (or their derivatives) prior to on‐resin Asp‐Lys lactam cyclization.…”