BioE Seminar: “Ice-binding-proteins and their interaction with ice crystals”

Seminar | January 25 | 12-1 p.m. | 290 Hearst Memorial Mining Building

 Ido Braslavsky

 Bioengineering (BioE)

Spring 2017 Seminar Series
Wednesday, January 25
12noon - 1:00pm
290 Hearst Mining Building

“Ice-binding-proteins and their interaction with ice crystals”

Professor Ido Braslavsky
The Robert H. Smith Faculty of Agriculture, Food and Environment,
The Hebrew University of Jerusalem, Rehovot, Israel
& Visiting Scholar at Stanford, Bioengineering

Ice-binding proteins (IBPs) are found in organisms that live under subfreezing temperature conditions. The list of such organisms continues to expand and includes, fish, insects, diatoms, plants, molds, and bacteria. IBPs depress the freezing point of the body fluids that prevents freezing of the organism in supercooled conditions, inhibits ice recrystallization, and enable adhesion to ice. The mechanisms by which IBPs interact with ice surfaces are still not completely understood, and the potential of IBPs as cryoprotecting agents for cryopreservation of cells, tissue, and organs, have not yet been realized. We are investigating the interactions of IBPs with ice surfaces. In particular, we investigate the dynamic nature of the protein&ice interaction using fluorescence microscopy techniques combined with temperature-controlled microfluidic devices. The results show that binding of IBP to ice is irreversible and that the freezing temperature depression is sensitive to the time allowed for the proteins to accumulate on ice surfaces. This time sensitivity changes dramatically between different types of IBPs. Our results relate the dynamics and level of activity of various types of IBPs to their ability to bind to specific ice orientations, in particularly to the basal plane of the ice. These results contribute to an understanding of the mechanisms by which IBPs act that will be critical for the successful use of IBP in cryobiological applications.