An Autocatalytic Peptide Cyclase Improves Fidelity and Yield of Circular Peptides In Vivo and In Vitro

Abstract

Peptide cyclization improves conformational rigidity, providing favorable pharmacological properties, such as proteolytic resistance, target specificity, and membrane permeability. Thus, many synthetic and biosynthetic peptide circularization strategies have been developed. PatG and related natural macrocyclases process diverse peptide sequences, generating millions of cyclic derivatives. However, the application of these cyclases is limited by low yields and the potential presence of unwanted intermediates. Here, we designed a covalently fused G macrocyclase with substrates that efficiently and spontaneously release cyclic peptides. To increase the fidelity of synthesis, we developed an orthogonal control mechanism enabling precision synthesis in Escherichia coli. As a result, a library comprising 4.8 million cyclic derivatives was constructed, producing an estimated 2.6 million distinct cyclic peptides with an improved yield and fidelity.

Chemo-enzymatic total synthesis: current approaches toward the integration of chemical and enzymatic transformations

“…In the chemical synthesis of macrolides, macrolactone construction most generally involves the generation of activated esters from the corresponding carboxylic acids followed by intramolecular condensation. As a chemo-enzymatic complementary strategy, thioesterase (TE) domains of NRPS and PKS gene clusters have been utilized as enzymes for macrolactone formation to produce a wide range of natural/non-natural macrocyclic compounds [ 58 – 63 ]. In the field of chemo-enzymatic total synthesis utilizing polyketide synthase (PKS)-related macrocyclization enzymes, Xiang and co-workers recently reported the total synthesis of cylindrocyclophanes [ 64 ].…”