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Updated: Jun 29, 2026

Determining the Ice-binding Planes of Antifreeze Proteins by Fluorescence-based Ice Plane Affinity
Published on: January 15, 2014
Cooperative function of ammonium polyacrylate with antifreeze protein type I
Kunio Funakoshi1, Takaaki Inada, Hiroshi Kawabata
1National Institute of Advanced Industrial Science and Technology, 1-2-1 Namiki, Tsukuba, Ibaraki 305-8564, Japan.
Abstract:
Activity of antifreeze proteins (AFPs) and antifreeze glycoproteins (AFGPs) is often determined by thermal hysteresis, which is the difference between the melting temperature and the nonequilibrium freezing temperature of ice in AF(G)P solutions. In this study, we confirmed that thermal hysteresis of AFP type I is significantly enhanced by a cooperative function of ammonium polyacrylate (NH4PA). Thermal hysteresis of mixtures of AFP type I and NH4PA was much larger than the sum of each thermal hysteresis of AFP type I and NH4PA alone. In mixed solutions of AFP type I and NH4PA in the thermal hysteresis region, hexagonal pyramidal-shaped pits densely formed on ice surfaces close to the basal planes. The experimental results suggest that the cooperative function of NH4PA with AFP type I was caused either by the increase in adsorption sites of AFP type I on ice or by the adsorption of AFP type I aggregates on ice.
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