Selective Activation of Peptide-Thioester Precursors for Templated Native Chemical Ligations.

Chemical protein synthesis enables access to proteins that would otherwise be difficult or impossible to obtain with traditional means such as recombinant expression. Chemoselective ligations provide the ability to join peptide segments prepared by solid-phase peptide synthesis. While native chemical ligation (NCL) is widely used, it is limited by the need for C-terminal thioesters with suitable reaction kinetics, properly placed native Cys or thiolated derivatives, and peptide segment solubility at low mM concentrations.

Generation of Potent and Stable GLP-1 Analogues Via "Serine Ligation".

Peptide and protein bioconjugation technologies have revolutionized our ability to site-specifically or chemoselectively install a variety of functional groups for applications in chemical biology and medicine, including the enhancement of bioavailability. Here, we introduce a site-specific bioconjugation strategy inspired by chemical ligation at serine that relies on a noncanonical amino acid containing a 1-amino-2-hydroxy functional group and a salicylaldehyde ester. More specifically, we harness this technology to generate analogues of glucagon-like peptide-1 that resemble Semaglutide, a long-lasting blockbuster drug currently used in the clinic to regulate glucose levels in the blood.

Traceless Click-Assisted Native Chemical Ligation Enabled by Protecting Dibenzocyclooctyne from Acid-Mediated Rearrangement with Copper(I).

The scope of proteins accessible to total chemical synthesis via native chemical ligation (NCL) is often limited by slow ligation kinetics. Here we describe Click-Assisted NCL (CAN), in which peptides are incorporated with traceless "helping hand" lysine linkers that enable addition of dibenzocyclooctyne (DBCO) and azide handles. The resulting strain-promoted alkyne-azide cycloaddition (SPAAC) increases their effective concentration to greatly accelerate ligations.

Enhancing native chemical ligation for challenging chemical protein syntheses.

Native chemical ligation has enabled the chemical synthesis of proteins for a wide variety of applications (e.g., mirror-image proteins).

Aligator: A computational tool for optimizing total chemical synthesis of large proteins.

The scope of chemical protein synthesis (CPS) continues to expand, driven primarily by advances in chemical ligation tools (e.g., reversible solubilizing groups and novel ligation chemistries).