title: Hexagonal shaped ice spicules in frozen antifreeze protein solutions.
abstract: In the presence of antifreeze proteins from both Antarctic and Arctic fishes, water freezes in the form of long c-axis spikes or spicular-like crystals. Transmission electron microscopy of the Pt/C replicas of the freeze fractured spicular ice in a small capillary revealed the presence of many hexagonally shaped structures whose cross-sectional dimensions were between 0.5 and 10 microm. Well-defined parallel faces were associated with most fractured and etched spicules. When fracture planes occurred near the tip of a spicule, well-defined pyramidal faces were apparent. Steps were sometimes associated with these pyramidal spicular crystal faces. On some of the replicas obvious roughening of certain crystal faces of the spicule was observed, suggesting that the antifreeze proteins may have adsorbed to those faces.
authors.affiliation: Department of Physiology, Medical School, University of Otago, P.O. Box 913, Dunedin, New Zealand. peter.wilson@stonebow.otago.ac.nz
authors.forename: P W
authors.initials: PW
authors.lastname: Wilson
authors.forename: M
authors.initials: M
authors.lastname: Gould
authors.forename: A L
authors.initials: AL
authors.lastname: DeVries
mesh_terms: D000327:Adsorption; D000818:Animals; D000864:Antarctic Regions; D021301:Antifreeze Proteins / Q000737:chemistry*; D001110:Arctic Regions; D005399:Fishes; D005614:Freeze Fracturing; D005615:Freezing; D007053:Ice; D066298:In Vitro Techniques; D008854:Microscopy, Electron; D012996:Solutions
chemical_list: D021301:Antifreeze Proteins; D007053:Ice; D012996:Solutions