Synthetic Antifreeze Could Prevent Ice Growth

A way to make large amounts of artificial antifreeze safe enough to use in living organisms has been developed by researchers looking at the “biological” antifreeze used by Arctic and Antarctic teleost fish, according to a report in the September/October issue of Bioconjugate Chemistry, a peer-reviewed journal of the American Chemical Society, the world’s largest scientific society. The report will be presented August 30 at the Society’s 222nd national meeting in Chicago.

A big problem with the freezing process in medical and industrial applications is that the formation of ice crystals damages living material. Certain organisms like the fish, however, have developed a successful defense — a naturally produced antifreeze called antifreeze glycoprotein, or AFGP. The biological AFGP in fish, and in some amphibians, plants and insects, prevents the growth of ice in those life forms, scientists have found.

While researchers have known about the glycoproteins for many years, they have been unable to produce large or stable enough copies for commercial applications, and the use of the natural compounds themselves is too labor and cost-intensive to be practical.

Even though researchers do not precisely understand the mechanism by which the AFGPs function, they have been able to modify the structure of the fish AFGP enough to build a longer lasting mimic, a lot like the native AFGPs, according to Robert Ben, Ph.D., who led the research team from the State University of New York in Binghamton. Ben says the new method can easily produce large quantities of the compound that yield only to inhospitable conditions like extremely high or low temperatures.

The new synthetic proteins “are dramatically different from the natural antifreeze glycoprotein, but still display the ability to inhibit ice growth,” Ben said. “This is very significant and may mean a real leap forward in the design of such compounds; we think this is incredibly promising for a number of applications.”

Among potential uses for synthetic AFGP’s: a frost protection spray for crops that could expand growing seasons and even allow fruits to grow in more northern climates. He also believes elimination of freezer burn is possible, along with the preservation of human organs and tissues for transplantation.

In essence, Ben reports, the new method replaces a weak chemical bond in the natural antifreeze with a far more durable one, but further study to develop greater strength in the artificial glycoprotein is ongoing. He said he anticipates that researchers will construct different variations of the modified antifreeze for different applications.

The research cited above was funded by the American Chemical Society, the U.S. National Institutes of Health and A/F Protein, a biotechnology firm in Waltham, Mass.