Determination of Melting Point of Antifreeze Protein by Open Capillary Method (CAT#: STEM-PPA-0068-YJL)

Introduction

Antifreeze proteins (AFPs) lower the non-equilibrium freezing point of an aqueous solution while not significantly affecting the melting point. This difference in melting and freezing points has been termed thermal hysteresis. AFPs naturally found in freeze avoiding insects depress the supercooling point (SCP) (nucleation temperature) of the organisms. During winter, AFPs of the freeze avoiding larvae of the beetle Dendroides canadensis function (1) to prevent inoculative freezing across the cuticle initiated by external ice and (2) to inhibit ice nucleators, both in the gut and hemolymph, thereby promoting supercooling. Exogenous AFPs have been expressed in fish, Drosophila melanogaster, and plants. Most studies have been able to produce low levels of AFPs in their respective organisms.