Abstract: Studies on insect antifreeze proteins have focused on several species, so far over twenty antifreeze proteins (AFPs) had been isolated. This paper reviews the present state of knowledge of antifreeze protein structure, composition, bioactivity, biosynthesis and the application of these substances. The secondary structure of AFPs is mainly β-sheet and turns and their most striking feature is the occurance of cysteines every six residues throughout their length. Almost all Cys residues are disulfide-bridged, which imposes significant structural constraints. Understanding the factors that affect AFP activity, such as activating proteins and low molecular solutes, is important for further progress in AFP research.

Key words: insect, antifreeze protein, thermal hysteresis