huji Institute of Biochemistry, Food Science and Nutrition

Robert H. Smith Faculty of Agriculture, Food and Environment,
The Hebrew University of Jerusalem

Dr. Ido Braslavsky

Prof. Ido Braslavsky

The lab

Many organisms are protected from freezing by antifreeze proteins (AFPs), which bind to ice, modify its morphology, and prevent its further growth.  Since the initial discovery of AFPs in fish, the have been found in insects, plants, bacteria and fungi.  These proteins have a wide range of applications in cryomedicine, cryopreservation and frost protection for transgenic plants and vegetables. AFPs also serve as a model for understanding biomineralization, the processes by which proteins help form bones, teeth and shells.  Yet the mechanism of action of different types of antifreeze proteins is incompletely understood.

In Braslavsky’s group, the kinetics of the interaction between AFP and ice is monitored by fluorescence microscopy.  Several types of AFPs labeled with a fluorescent marker have been prepared mainly by our collaborator Peter Davies.  By putting a fluorescent tag on a fish AFP, we were able to directly visualize AFP binding to ice and demonstrate, by lack of recovery after photo-bleaching, that a fish AFP from ocean pout (type III) adheres irreversibly to ice surfaces.  Additionally, we observed fluorescently labeled hyperactive insect antifreeze protein from spruce budworm on ice crystals.  We find that differences between antifreeze protein types are manifested not only by the shape of the ice crystals but also in the way proteins interact with the ice.

We are currently developing devices that can monitor the fluorescently labeled proteins with high sensitivity.  In collaboration with professor Alex Groismann from UCSD, Braslavsky’s group developed microfluidic devices in which the composition of the solution around tiny ice crystals can be changes.  We plan to use these devices soon to further explore the behaviors of the antifreeze proteins and their interaction with ice.  The system of AFPs and ice can be used as a model platform to understand bio-mineralization processes and thus its importance for future nanotechnology applications. 

ERC project: Improved Cryopreservation using Ice Binding Proteins
פרופ' עידו ברסלבסקי מהמכון לביוכימיה, מדעי המזון והתזונה בפקולטה לחקלאות, מזון וסביבה ע"ש רוברט ה. סמית, קיבל את המענק בסך 1,500,000 יורו בעבור מחקרו בנושא שימור בקירור על-ידי חלבונים נצמדי קרח. חלבונים נצמדי קרח מונעים את גדילתם של אורגניזמים רבים ובכך מפחיתים את נזקי הקפיאה שלהם. מענק המחקר מהאיחוד האירופאי הוענק לפרופ' ברסלבסקי לצורך מחקר בסיסי של חלבונים נצמדי קרח ושיפור שימור בקור. פרופ' ברסלבסקי מסביר כי שילוב יעיל של חלבונים נצמדי קרח בשימור בקור יכול להביא למהפכה ביישומים בהם נדרשת שליטה בקפיאה כגון שימור רקמות ואיברים בקור, הגנה מפני נזקי קרה בחקלאות ושיפור איכות המזון הקפוא.

Marie Curie Reintegration Grant: Freeze Control in Food by Ice Binding Proteins
K&E Design
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