(485bb) Foldon Attachment to the Type III Antifreeze Protein Increases Thermal Hysteresis Activity | AIChE

(485bb) Foldon Attachment to the Type III Antifreeze Protein Increases Thermal Hysteresis Activity

Authors 

Can, Ö. - Presenter, University of Delaware
Ghoorchian, A. - Presenter, Cleveland State University
Holland, N. B. - Presenter, Cleveland State University


Antifreeze proteins (AFPs) are ice binding proteins found in some plants, insects and fish living in extereme environments where an adaptation to life is made possible by the ice crystal growth inhibition phenomena observed at subzero temperatures. By binding to an ice crystal, AFPs cause the formation of ice surface curvatures between the adsorbed protein molecules that prevents further growth energetically unfavorable and hence lower the freezing point of the solution. The extent of this activity is commonly measured by the thermal hysteresis, which is the difference between freezing and melting temperatures.

The interesting properties of AFPs attracted significant attention and have made them suitable candidates in different application areas such as subzero preservation of cells, tissues or organs, frozen foods and heat transfer fluids in refrigeration systems. However, an increased understanding of how AFPs play a role in ice binding is necessary to design novel synthetic molecules that have better thermal hysteresis activities especially at very low concentrations.

In this study, a type III AFP from Antarctic eel pout is used to create a construct in an E.Coli expression system that would fold in a three domain structure using an oligomerization domain called foldon, which is found in bacteriophage T4 fibritin. This new molecule folds into the desired confirmation and therefore creates a trimer in the solution significantly increasing the thermal hysteresis activity of the AFP especially at very low concentrations.