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.

Key words: Arnrnopiptanthas rnongolicus, Antifreeze protein