Enzyme‐Cleavable Linkers for Protein Chemical Synthesis through Solid‐Phase Ligations

Abstract

The total synthesis of long proteins requires the assembly of multiple fragments through successive ligations. The need for intermediate purification steps is a strong limitation, particularly in terms of overall yield. One solution to this problem would be solid‐supported chemical ligation (SPCL), for which a first peptide segment must be immobilized on a SPCL‐compatible solid support through a linker that can be cleaved under very mild conditions to release the assembled protein. The cleavage of SPCL linkers has previously required chemical conditions sometimes incompatible with sensitive protein targets. Herein, we describe an alternative enzymatic approach to trigger cleavage under extremely mild and selective conditions. Optimization of the linker structure and use of a small enzyme able to diffuse into the solid support were key to the success of the strategy. We demonstrated its utility by the assembly of three peptide segments on the basis of native chemical ligation to afford a 15 kDa polypeptide.

Selective synthesis of α- and β-glycosides of N-acetyl galactosamine using rare earth metal triflates

“…β -glycosides of GalNAc or galactose are common structures constructed for different applications, such as substrates of β -galactosidase for selective release ( Thomas et al, 2011 ; Abboud et al, 2021 ). Therefore, we next focus our attention on the optimization of β -GalNAc glycosides with various reaction conditions, including changed ratios of the donor and acceptor and the equivalent of Sc(OTf) 3.…”