Polyvalent Thioesters as Multifunctional Chemical Anchors: Toward Synthesis of Homo/Hetero Peptide or Miniprotein Multimers

In this work, we develop a platform for multimerizing peptides/miniproteins using various polyvalent thioester cores derived from easy-to-synthesize N-hydroxysuccinimide esters. We employed native chemical ligation to attach multiple copies of peptide/miniprotein around a fixed multi-armed thioester core in a one-pot fashion, leading to the first-generation multimers. Further, using a reverse thioether ligation strategy, we synthesized second-generation branched homo/hetero multimers. The reactions proceed under an aqueous environment that closely mimics physiological conditions, forming multimeric products with yields ranging from 30% to 90%. The general utility of this strategy is showcased by the synthesis of multimeric linear and bicyclic peptides, bicyclic peptide-cell penetrating peptide conjugates, and multimeric miniproteins which show picomolar affinity against SARS-CoV-2 receptor binding domain. We believe that this modular approach of generating multimeric molecules should find broad applicability in peptide chemistry and chemical biology.