Heterochiral and Heterotypic Self-Assembly of Intrinsically Disordered Peptides Confers Peptide Supercoils with Exceptional Proteolytic Stability

Abstract

Chirality has received extensive exploration in homotypic supramolecular assemblies; however, few heterotypic peptide assemblies employ heterochirality, especially in the context of intrinsically disordered peptides (IDPs). In this work, we show that heterochiral, heterotypic assemblies of IDPs unexpectedly form supercoils of nanofibers. Specifically, conjugating an aromatic motif to IDPs with opposite charge and chirality results in positively and negatively charged IDPs that form supercoils when mixed in a 2:1 ratio. These supercoils significantly modulate the enzymatic stability of l-peptides: they prevent the proteolysis of l-peptides when the d-peptide to l-peptide ratio is 2:1 but promote it when the ratio is 1:2. Moreover, the formation of supercoils enhances the stability of post-translational modification, phosphotyrosine, against a powerful phosphatase. This work presents the first case of heterochiral and heterotypic assemblies of IDPs. It offers a novel and facile approach for designing supramolecular materials made of IDPs with tunable enzymatic stability. These materials promise applications in a variety of in vivo settings, particularly when efficacy depends on enzymatic stability of IDPs.