A minimalistic cyclic ice-binding peptide from phage display

Corey A Stevens,Luciano A Abriata,Gabriele C Sosso,Matthew I Gibson,Xu-Dong Kong,Fabienne Bachtiger,Harm-Anton Klok

doi:10.1038/s41467-021-22883-w

Abstract

Developing molecules that emulate the properties of naturally occurring ice-binding proteins (IBPs) is a daunting challenge. Rather than relying on the (limited) existing structure–property relationships that have been established for IBPs, here we report the use of phage display for the identification of short peptide mimics of IBPs. To this end, an ice-affinity selection protocol is developed, which enables the selection of a cyclic ice-binding peptide containing just 14 amino acids. Mutational analysis identifies three residues, Asp8, Thr10 and Thr14, which are found to be essential for ice binding. Molecular dynamics simulations reveal that the side chain of Thr10 hydrophobically binds to ice revealing a potential mechanism. To demonstrate the biotechnological potential of this peptide, it is expressed as a fusion (‘Ice-Tag’) with mCherry and used to purify proteins directly from cell lysate.

Highlights

Developing molecules that emulate the properties of naturally occurring ice-binding proteins (IBPs) is a daunting challenge
Rather than building upon existing structural know-how, this study explores the use of phage display, a biological, combinatorial discovery tool, for the identification of short peptide mimics of IBPs
This may help to provide further structural insight into the key structural determinants that govern the properties of IBPs

Summary

Introduction

Developing molecules that emulate the properties of naturally occurring ice-binding proteins (IBPs) is a daunting challenge. The solution structure of the peptide is characterized by NMR spectroscopy, and mutational analysis experiments reveal three residues, Asp[8], Thr[10] and Thr[14], which are found to be essential for ice binding.

Results

Conclusion