Advances in
Fish Antifreeze Protein Research
ZHONG Qi-Wang, FAN Ting-Jun*
( Department of Marine Biology , College of Marine Life Sciences, Ocean
University of Qingdao, Qingdao 266003, China )
Abstract Antifreeze
proteins (AFPs) can highly effectively protect cells and embryos from damages
in freezing process by lowering the freezing points of their cytoplasmic matrix
and body fluids in a noncolligative manner. Based on their origins and
properties, AFPs have been classified into four types, i.e. type I, II, III and
IV. Each of them possesses rather distinct characteristics both in structure
and composition, although all of them have ability of lowering freezingpoints
of fluids. AFPs’ genes have been characterized as members of a multigene family
and the levels of their mRNA synthesis vary significantly with seasons.
Adsorption-inhibition operating at the ice surface is nowadays a hypothesis
widely used to interpret the molecular mechanisms of noncolligative lowering of
the freezing point, but the details of the mechanism on how the different types
of AFP are adsorbed onto ice remain uncertain. Progresses in research on structures,
amino acid compositions, genes, antifreeze mechanisms of the 4 distinct types
of AFPs, and the application of the AFPs in cryopreservation of cells and
embryos are reviewed here.
Key words antifreeze proteins； antifreeze mechanism； cryopreservation
*Corresponding author： Tel, 0532-2032459； Fax, 0532-2032276； e-mail： [email protected]