Biomolecules
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.
Published: September 2019
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.
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http://dx.doi.org/10.3390/biom9100532 | DOI Listing |
J Am Chem Soc
January 2025
Department of Materials Science and Engineering, City University of Hong Kong, Hong Kong, Kowloon 999077, China.
Heterogeneous ice nucleation is a widespread phenomenon in nature. Despite extensive research on ice nucleation near biological antifreeze proteins, a probe for ice nucleation and growth processes at the atomic level is still lacking. Herein, we present simulation evidence of the heterogeneous ice nucleation process on the ice-binding surface (IBS) of the antifreeze protein (TmAFP).
View Article and Find Full Text PDFVet Res Commun
January 2025
Faculty of Agriculture, University Farm, Utsunomiya University, Tochigi, 321-4415, Japan.
The purpose of this study was to improve the quality of frozen-thawed canine spermatozoa through the optimization of glycerol concentration (GC) and freezing rate in the semen freezing protocol. Ejaculates from nine dogs were diluted with an extender containing 0%, 1.5%, 3%, 6%, or 9% glycerol.
View Article and Find Full Text PDFJ Food Sci
January 2025
Department of Human Nutrition, Food, and Animal Sciences, University of Hawai'i at Mānoa, Honolulu, Hawai'i, USA.
Freezing extends the shelf life of foods but often leads to structural damage due to ice crystal formation, negatively impacting quality attributes. Oscillating magnetic field (OMF)-assisted supercooling has emerged as a potential technique to overcome these limitations by inhibiting ice nucleation and maintaining foods in a supercooled state. Despite its potential, the effectiveness and underlying mechanisms of OMF-assisted supercooling remain subjects of debate.
View Article and Find Full Text PDFInt J Biol Macromol
January 2025
College of Food Science and Technology, Zhejiang University of Technology, Hangzhou 310014, China; Zhejiang Key Laboratory of Green, Low-carbon and Efficient Development of Marine Fishery Resources, Hangzhou 310014, China; National R&D Branch Center for Pelagic Aquatic Products Processing (Hangzhou), Hangzhou 310014, China. Electronic address:
Slurry ice preparation experiences considerable supercooling, which can be mitigated by nano-nucleating agents. A nano-nucleating agent (CH/PE-TP NPs) was prepared by ultrasonication-assistant self-assembly of chitosan (CH) and pectin (PE), encapsulated with tea polyphenols (TP). Ultrasonication for 10 min downsized self-assembled aggregates from 5.
View Article and Find Full Text PDFNano Lett
January 2025
Department of Biochemical Engineering, School of Chemical Engineering and Technology, State Key Laboratory of Synthetic Biology, Frontier Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (MOE), Tianjin University, Tianjin 300350, China.
Organisms that survive at freezing temperatures produce antifreeze proteins (AFPs) to manage ice nucleation and growth. Inspired by AFPs, a series of synthetic materials have been developed to mimic these proteins in order to avoid the limitations of natural AFPs. Despite their great importance in various antifreeze applications, the relationship between structure and performance of AFP mimics remains unclear, especially whether their molecular charge-specific effects on ice inhibition exist.
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