# Spontaneous Formation of a Sustainable Antifreeze Coating by Peptide Self-Assembly

## TL;DR

Researchers created a sustainable antifreeze coating using self-assembling peptides inspired by natural proteins, showing promise for preventing ice formation in various applications.

## Contribution

A novel peptide design combining antifreeze and adhesion properties from natural proteins to form a sustainable antifreeze coating.

## Key findings

- Surfaces coated with AFPep1 delayed initial freezing by 5 °C compared to bare surfaces.
- AFPep1 inhibited ice recrystallization at 0.5 ± 0.1 mM concentration.
- AFPep1 shaped ice crystals into hexagonal plates and inhibited ice growth at supercooling levels up to 0.04 °C.

## Abstract

The formation of ice and frost on surfaces poses significant
challenges
to aviation, crop protection, organ preservation, and other fields.
This paper presents the formation of sustainable antifreeze coating
by the self-assembly of short peptides. The peptide design is inspired
by and combines different elements from distinct natural proteins:
(i) a sequence of amino acids from an antifreeze protein and (ii)
the amino acids 3,4-dihydroxyphenylalanine (DOPA) and lysine from
mussel adhesion proteins that anchor the peptide to a surface. The
peptide, termed AFPep1, incorporates the repetitive ice-binding motif
found in the antifreeze protein of the longhorn beetle (Rhagium inquisitor). Surfaces coated with the peptide
exhibited antifreeze activity with a delay of the initial freezing
of 5 °C degrees compared to a bare surface. Furthermore, AFPep1
exhibited relatively effective ice recrystallization inhibition (IRI)
activity in solution compared to various other common substances,
with an inhibition concentration of 0.5 ± 0.1 mM. Additionally,
the presence of AFPep1 in the solution shaped ice crystals into hexagonal
plates, indicating specific binding to ice. Moreover, thermal hysteresis
results show that AFPep1 completely inhibits ice growth at supercooling
levels of up to 0.04 °C at 2 mM, indicating the peptide’s
ability to self-assemble and create high-density anchoring points
on the ice surface. These results highlight the significant potential
of specific peptides as antifreeze coatings for technological infrastructure
and agricultural applications.