Development of ULYSSIS, a Tool for the Biosynthesis of Cyclotides and Cyclic Knottins

Abstract

Many human disorders and discomforts can potentially be treated by peptide-based medicines. There are two major problems in using peptide-based medicines: their stability and cost-effective production. Generating cyclic variants of linear peptides is an effective way to improve in vivo stability, if done correctly it is possible to retain native activity. In this paper we describe use of peptide complementation to delay splicing and facilitate purification by affinity tag, through ULYSSIS (Universal Ligation bY a Secondarily Split Intein System), a conditional split intein based peptide cyclisation system. Through ULYSSIS we have generated two proof of concept cyclic peptides, kalata B1 and a cyclic variant of a small natively linear peptide, leconotide.