Research Interests
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
ERC project: Improved Cryopreservation using Ice Binding Proteins
http://newsletter.huji.ac.il/article.php?ID=103
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.
Several organisms have evolved specialized ice binding proteins (IBPs) that prevent their body fluids from freezing (antifreeze proteins, AFPs), inhibit recrystallization of ice in frozen tissues, or initiate freezing at moderate supercooling temperatures (ice nucleating proteins, INPs). These proteins have many potential applications in agriculture, food preservation, cryobiology, and biomedical science. The ubiquitous presence of IBPs in such organisms indicates the power of these molecules to enable survival under cold conditions. Despite this key role in nature, however, IBPs have been effectively exploited in only one cryopreservation application, namely, recrystallization inhibition in ice cream. Several terrestrial organisms, including insects, have developed very active forms of AFPs. These hyperactive AFPs (hypAFPs) have not been utilized significantly thus far in cryopreservation techniques. The gap between the obvious potential of IBPs and their actual applications stems from a lack of knowledge regarding the mechanisms by which IBPs interact with ice surfaces and how these proteins can assist in cryoprotection. I propose to investigate the mechanism by which IBPs inhibit ice crystallization and the use of such proteins for cryopreserving cells, tissues, and organisms. My group has a strong record in the study of the interactions between IBPs and ice using novel methods that we have developed, including fluorescence microscopy techniques combined with cooled microfluidic devices. We will investigate the interactions of AFPs with ice and the use of hypAFPs in cryopreservation procedures. This research will contribute to an understanding of the mechanisms by which IBPs act, and apply the acquired knowledge to cryopreservation. The successful implementation of IBPs in cryopreservation would revolutionize the field of cryobiology, with enormous implications for cryopreservation applications in general and the frozen and chilled food industry in particular.
IRG project: Freeze Control in Food by Ice Binding Proteins
Marie Curie Reintegration Grants abstract:
The freezing processes play a main role in food science. The storage of food in a frozen form has become one of the most common ways to elongate the shelf-time of many food products. Nevertheless, during freezing and thawing, cell walls can be ruptured by the ice crystals or can be separated by extra-cellular ice growth during the recrystalization process. Ice binding proteins (IBP), which include antifreeze proteins, ice nucleating proteins, and recrystalization inhibitors, hold great promise for improvements in food supply and quality through the prevention of frost damage to crops and the enhancement of preservation technology. The interaction of IBPs with ice crystals suggests that these proteins can be use as a means of controlling ice in food in each level of its production and processing. I propose to investigate freeze control in food by ice binding proteins. My background includes a PhD in ice physics and in particular optical investigation of crystal growth, a post-doctorate work in biophysics and biotechnology and academic position in Ohio University in where I investigate IBPs. In my post-doctorate work at Caltech, I developed instrumentation that was the basis for the biotechnology company Helicos Bioscience, which led to the development of the first instrumentation that can sequence DNA at the single molecule level. In the past few years at Ohio University, I have combined the subjects of ice physics and biophysics and have developed methods for investigating antifreeze proteins in novel ways. I have developed unique instrumentation to assess the activity of the proteins, in particular microfluidics and fluorescence microscopy. At the Hebrew University Faculty of Agriculture, Food and Environment I intend to establish a Food Biophysics lab in which I will continue my basic research on the mechanism of freeze control and investigate the potential of IBPs to improve the quality of different food materials upon cooling, freezing and thawing.