Rational Design of and Mechanism Insight into an Efficient Antifreeze Peptide for Cryopreservation

The development of effective antifreeze peptides to control ice growth has attracted a significant amount of attention yet still remains a great challenge. Here, we propose a novel design method based on an in-depth investigation of repetitive motifs in various ice-binding proteins (IBPs) with an evolution analysis. In this way, several peptides with notable antifreeze activity were developed. In particular, a designed antifreeze peptide named AVD exhibits ideal ice recrystallization inhibition (IRI), solubility, and biocompatibility, making it suitable for use as a cryoprotective agent (CPA). A mutation analysis and molecular dynamics (MD) simulations indicated that the Thr6 and Asn8 residues of the AVD peptide are fundamental to its ice-binding capacity, while the Ser18 residue can synergistically enhance their interaction with ice, revealing the antifreeze mechanism of AVD. Furthermore, to demonstrate the cryoprotection potential of AVD, the peptide was successfully employed for the cryopreservation of various cells, which demonstrated significant post-freezing cell recovery. This work opens up a new avenue for designing antifreeze materials and provides peptide-based functional modules for synthetic biology.