(5)對於分子量較大的抗凍蛋白，例如Type II AFPs，其一個
分子量較小的抗凍蛋白，例如Type I AFPs，其蛋白的合作數
Structural Characteristics of the Antifreeze
Proteins (AFP) and Glycoproteins (AFGP)
AFP Type I
2,600 - 33,000
3,300 - 4,500
AFP Type II
Fish antifreeze proteins - applications
In years to come, blood products may be stored for longer periods of time, a therapy for
hypothermia may be developed, and a salmon with superior growth capabilities may
Study cold water adaptation in fish with an emphasis on the antifreeze proteins found in
their blood. These vital proteins prevent ice crystals from growing in the blood when
the water temperature is very low, thus preventing the fish from freezing.
Atlantic salmon do not possess antifreeze proteins and therefore are unable to be
cultured in sub-zero waters off the Atlantic coast of Canada. In order to make salmon
more freeze resistant, Dr. Fletcher injected antifreeze protein genes into salmon eggs.
These genes were incorporated into the salmon's chromosomes and so far they have
passed on through three successive generations of salmon.
However, as Dr. Fletcher explained, "The levels of antifreeze found in the salmon are
low; thus, although the results are promising, more research is required before this
salmon broodstock will be of value to industry."
This is not the only research ongoing to improve the performance of salmon for
aquaculture. In 1990 Dr. Fletcher and his colleague, Dr. Choy Hew of the University of
Toronto, developed a gene that contained a salmon growth hormone and antifreeze
component. When Dr. Fletcher's team injected this gene into the salmon eggs, the
resulting transgenic salmon grew four to six times faster than standard salmon.