An Ultra-Potent, Ultra-Economical, Antifreeze Polypeptide

The coarsening of ice crystals during freeze and thaw events is a challenge in diverse settings from transportation and agriculture to foods and biomedicine. Design, synthesis, and evaluation of antifreeze polypeptides that inhibit ice crystal growth at μg concentrations are reported herein. The polypeptides, composed of Ala and Glu, were prepared using economical methodology, are thermally stable, are biodegradable, and are non-toxic to human cells. Mirror-image polypeptides resisted degradation and are suitable for applications with a longevity criterion. Their α-helical conformation played a role in antifreeze activity, but chirality did not. In proof-of-concept experiments, the antifreeze polypeptides could prevent damage to model protein therapeutics during repeated freeze-thaw cycles, and could be applied to prevent large ice crystals in a frozen food product. These simple, economical Ala/Glu polypeptides are promising materials for diverse antifreeze applications, particularly in biological settings.