title: Janus effect of antifreeze proteins on ice nucleation.
abstract: The mechanism of ice nucleation at the molecular level remains largely unknown. Nature endows antifreeze proteins (AFPs) with the unique capability of controlling ice formation. However, the effect of AFPs on ice nucleation has been under debate. Here we report the observation of both depression and promotion effects of AFPs on ice nucleation via selectively binding the ice-binding face (IBF) and the non-ice-binding face (NIBF) of AFPs to solid substrates. Freezing temperature and delay time assays show that ice nucleation is depressed with the NIBF exposed to liquid water, whereas ice nucleation is facilitated with the IBF exposed to liquid water. The generality of this Janus effect is verified by investigating three representative AFPs. Molecular dynamics simulation analysis shows that the Janus effect can be established by the distinct structures of the hydration layer around IBF and NIBF. Our work greatly enhances the understanding of the mechanism of AFPs at the molecular level and brings insights to the fundamentals of heterogeneous ice nucleation.
authors.affiliation: Key Laboratory of Green Printing, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, People's Republic of China.|School of Chemistry and Chemical Engineering, University of Chinese Academy of Sciences, Beijing 100049, People's Republic of China.
authors.forename: Kai
authors.initials: K
authors.lastname: Liu
authors.affiliation: Division of Interfacial Water and Key Laboratory of Interfacial Physics and Technology, Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800, People's Republic of China; wangj220@iccas.ac.cn wangchunlei@sinap.ac.cn.
authors.forename: Chunlei
authors.initials: C
authors.lastname: Wang
authors.affiliation: Xinjiang Key Laboratory of Biological Resources and Genetic Engineering, College of Life Science and Technology, Xinjiang University, Urumqi 830046, People's Republic of China.
authors.forename: Ji
authors.initials: J
authors.lastname: Ma
authors.affiliation: Division of Interfacial Water and Key Laboratory of Interfacial Physics and Technology, Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800, People's Republic of China.
authors.forename: Guosheng
authors.initials: G
authors.lastname: Shi
authors.affiliation: Key Laboratory of Green Printing, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, People's Republic of China.
authors.forename: Xi
authors.initials: X
authors.lastname: Yao
authors.affiliation: Division of Interfacial Water and Key Laboratory of Interfacial Physics and Technology, Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800, People's Republic of China.
authors.forename: Haiping
authors.initials: H
authors.lastname: Fang
authors.affiliation: Key Laboratory of Green Printing, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, People's Republic of China.|School of Chemistry and Chemical Engineering, University of Chinese Academy of Sciences, Beijing 100049, People's Republic of China.
authors.forename: Yanlin
authors.initials: Y
authors.lastname: Song
authors.affiliation: Key Laboratory of Green Printing, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, People's Republic of China; wangj220@iccas.ac.cn wangchunlei@sinap.ac.cn.|School of Chemistry and Chemical Engineering, University of Chinese Academy of Sciences, Beijing 100049, People's Republic of China.
authors.forename: Jianjun
authors.initials: J
authors.lastname: Wang
mesh_terms: D000818:Animals; D021301:Antifreeze Proteins / Q000737:chemistry*; D003080:Cold Temperature; D001517:Coleoptera; D003460:Crystallization; D030562:Databases, Protein; D004298:Dopamine / Q000737:chemistry; D005399:Fishes; D005615:Freezing; D007053:Ice; D053544:Marinomonas; D018625:Microscopy, Atomic Force; D056004:Molecular Dynamics Simulation; D011485:Protein Binding; D012984:Software; D013499:Surface Properties; D014867:Water / Q000737:chemistry
chemical_list: D021301:Antifreeze Proteins; D007053:Ice; D014867:Water; D004298:Dopamine
keywords: Janus effect; antifreeze proteins; ice nucleation; interfacial water; selective tethering