Kinetic pinning and biological antifreezes

TL;DR

This paper develops a comprehensive kinetic theory explaining how antifreeze proteins inhibit ice growth in cold-water organisms, accurately modeling freezing point suppression based on protein concentration and geometry.

Contribution

It introduces a complete kinetic model for antifreeze proteins' mechanism, providing quantitative predictions and insights into designing synthetic antifreezes.

Findings

Quantitative agreement with experimental freezing point suppression data

Dependence of suppression on protein geometry accurately modeled

Potential for guiding synthetic antifreeze development

Abstract

Biological antifreezes protect cold-water organisms from freezing. An example are the antifreeze proteins (AFPs) that attach to the surface of ice crystals and arrest growth. The mechanism for growth arrest has not been heretofore understood in a quantitative way. We present a complete theory based on a kinetic model. We use the `stones on a pillow' picture. Our theory of the suppression of the freezing point as a function of the concentration of the AFP is quantitatively accurate. It gives a correct description of the dependence of the freezing point suppression on the geometry of the protein, and might lead to advances in design of synthetic AFPs.