Contributes to protect body fluid from freezing at subzero temperatures. Lowers the freezing point of the hemolymph by about 2.5 degrees at a concentration of 1 mg/ml. Binds to nascent ice crystals and prevents further growth. Monomer. Forms a right-handed beta-helix that is stabilized by disulfide bonds. The building blocks of this beta-helix correspond to tandem repeats with the consensus sequence T-C-T-X-S-X-X-C-X-X-A-X. Belongs to the insect antifreeze protein family.