Abstract:The authors have isolated and partial purified antifreeze protein antifreeze protein (AFP) produced
endogenously in Arnrnopiptanthus rnongolicus. The results show that the partial purified AFP ranged in size
including 45.7 kD, 81.2 kD, and so on. At 50 mg/mL protein concentration, the temperature of melting point
is –15 ℃, and its freezing point is even lower. Therefore, the AFP activity exhibited by the
Arnmopiptanthus mongolicus is higher than that observed for AFP found in polar fishes or in winter rye. In
addition, by a phase contrast light photomicroscope, the author have observed the morphology of individual
ice crystals formed in the solution, including squares, rectangles, cones, hexagons. The morphology of these
ice crystals are similar to those of ice crystals observed in polar fishes and in cold-acclimation winter rye.