Ice Nucleation Properties of Ice-binding Proteins from Snow Fleas
Akalabya Bissoyi,
Naama Reicher,
Michael Chasnitsky,
Sivan Arad,
Thomas Koop,
Yinon Rudich,
Ido Braslavsky
Affiliations
Akalabya Bissoyi
The Robert H. Smith Faculty of Agriculture, Food and Environment, Institute of Biochemistry, Food Science, and Nutrition, The Hebrew University of Jerusalem, Rehovot 7610001, Israel
Naama Reicher
Department of Earth and Planetary Sciences, The Weizmann Institute of Science, Rehovot 7610001, Israel
Michael Chasnitsky
The Robert H. Smith Faculty of Agriculture, Food and Environment, Institute of Biochemistry, Food Science, and Nutrition, The Hebrew University of Jerusalem, Rehovot 7610001, Israel
Sivan Arad
The Robert H. Smith Faculty of Agriculture, Food and Environment, Institute of Biochemistry, Food Science, and Nutrition, The Hebrew University of Jerusalem, Rehovot 7610001, Israel
Thomas Koop
Bielefeld University, Faculty of Chemistry, D-33615 Bielefeld, Germany
Yinon Rudich
Department of Earth and Planetary Sciences, The Weizmann Institute of Science, Rehovot 7610001, Israel
Ido Braslavsky
The Robert H. Smith Faculty of Agriculture, Food and Environment, Institute of Biochemistry, Food Science, and Nutrition, The Hebrew University of Jerusalem, Rehovot 7610001, Israel
Ice-binding proteins (IBPs) are found in many organisms, such as fish and hexapods, plants, and bacteria that need to cope with low temperatures. Ice nucleation and thermal hysteresis are two attributes of IBPs. While ice nucleation is promoted by large proteins, known as ice nucleating proteins, the smaller IBPs, referred to as antifreeze proteins (AFPs), inhibit the growth of ice crystals by up to several degrees below the melting point, resulting in a thermal hysteresis (TH) gap between melting and ice growth. Recently, we showed that the nucleation capacity of two types of IBPs corresponds to their size, in agreement with classical nucleation theory. Here, we expand this finding to additional IBPs that we isolated from snow fleas (the arthropod Collembola), collected in northern Israel. Chemical analyses using circular dichroism and Fourier-transform infrared spectroscopy data suggest that these IBPs have a similar structure to a previously reported snow flea antifreeze protein. Further experiments reveal that the ice-shell purified proteins have hyperactive antifreeze properties, as determined by nanoliter osmometry, and also exhibit low ice-nucleation activity in accordance with their size.
