Isolates of 'Pseudomonas borealis' were recovered after ice-affinity selection of summer-collected soils. 'P. borealis' DL7 was further characterized and shown to have ice nucleation activity (INA), a property that allows the crystallization of ice at temperatures close to the melting point, effectively preventing the supercooling of water. INA was optimally detected after culturing at temperatures consistent with psychrophilic growth. The sequence encoding the 'P. borealis' ice nucleation protein (INP) was obtained using both PCR and chromosome walking. When expressed in Escherichia coli, the resulting inaPb recombinants had INA. The 'P. borealis' sequence, dubbed inaPb, is clearly related to previously cloned INP genes, but it shows greater divergence. Sequence analysis suggests that there are two opposite flat surfaces, one relatively hydrophobic that likely serves as an ice template, and the other that could function as a complementary face to facilitate interprotein interaction for ice-step formation.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1099/mic.0.025114-0 | DOI Listing |
Nano 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.
View Article and Find Full Text PDFJ Phys Chem Lett
January 2025
Université Claude Bernard Lyon 1, INSA Lyon, Université Jean Monnet, CNRS, UMR 5223, Ingénierie des Matériaux Polymères, F-69621 Villeurbanne Cédex, France.
Supercooling allows for retarding water crystallization toward negative Celsius temperatures. Previous findings of CO molecules shifting into bicarbonate species upon freezing, the latter which naturally adsorb on hydrophobic interfaces, are put in perspective here to interpret earlier published data. Since it has been shown that ice nucleation is unlikely on negatively charged surfaces, I propose that bicarbonates adsorb on most solid particles present in water that act as nucleators, thus retarding freezing and enhancing supercooling.
View Article and Find Full Text PDFiScience
November 2024
Research Center for Macromolecules and Biomaterials, National Institute for Materials Science (NIMS), 1-2-1 Sengen, Tsukuba, Ibaraki 305-0047, Japan.
Largely varied anti-icing performance among superhydrophobic surfaces remains perplexing and challenging. Herein, the issue is elucidated by exploring the roles of surface chemistry and surface topography in anti-icing. Three superhydrophobic surfaces, i.
View Article and Find Full Text PDFInt J Pharm
January 2025
Institute of Energy and Process Engineering, ETH Zurich, 8092 Zurich, Switzerland. Electronic address:
Numerous commercially available biopharmaceuticals are frozen or freeze-dried in vials. The temperature at which ice nucleates and its distribution across vials in a batch is critical to the design of freezing and freeze-drying processes. Here we study experimentally how the level of particulate impurities - a key parameter in pharmaceutical manufacturing - affects the ice nucleation behavior.
View Article and Find Full Text PDFJ Am Chem Soc
January 2025
Department of Chemistry and Biochemistry, University of California San Diego, La Jolla, California 92093, United States.
Ice interfaces are pivotal in mediating key chemical and physical processes such as heterogeneous chemical reactions in the environment, ice nucleation, and cloud microphysics. At the ice surface, water molecules form a quasi-liquid layer (QLL) with properties distinct from those of the bulk. Despite numerous experimental and theoretical studies, a molecular-level understanding of the QLL has remained elusive.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!