The denaturation of lipid-protein complexes as a cause of damage by freezing

The practice of cold storage for preserving labile material of biological origin is widespread. The general utility of this method and the successful preservation of living cells and tissues in the frozen state has overshadowed the fact that freezing can be a harmful process to living cells (Wood 1956). It used to be thought that the crushing or spearing action of ice crystal growth was the principal source of damage by freezing; indeed so reasonable is this theory that it is difficult to believe that some at least of the harmful effects of freezing are not due to this cause. The development of the theories of damage by ice crystal growth have been described in detail by Luyet & Gehenio (1940), and by Meryman (1956). By contrast with damage on a macroscopic scale which might occur during the growth of ice crystals there is evidence to show that freezing can damage the molecular constituents of living cells, and this is most unlikely to be a direct consequence of the intrusion of ice crystals. This aspect of the problem of freezing damage forms the basis of this paper.

CrystEngComm ◽  
2017 ◽  
Vol 19 (16) ◽  
pp. 2163-2167 ◽  
Author(s):  
Charles H. Z. Kong ◽  
Ivanhoe K. H. Leung ◽  
Vijayalekshmi Sarojini

Synthetic antifreeze peptides based on the hyperactive antifreeze protein modify the shape of ice crystals and show enhanced antifreeze activity with the addition of a small molecule.


2018 ◽  
Vol 115 (29) ◽  
pp. 7479-7484 ◽  
Author(s):  
Maddalena Bayer-Giraldi ◽  
Gen Sazaki ◽  
Ken Nagashima ◽  
Sepp Kipfstuhl ◽  
Dmitry A. Vorontsov ◽  
...  

Ice-binding proteins (IBPs) affect ice crystal growth by attaching to crystal faces. We present the effects on the growth of an ice single crystal caused by an ice-binding protein from the sea ice microalga Fragilariopsis cylindrus (fcIBP) that is characterized by the widespread domain of unknown function 3494 (DUF3494) and known to cause a moderate freezing point depression (below 1 °C). By the application of interferometry, bright-field microscopy, and fluorescence microscopy, we observed that the fcIBP attaches to the basal faces of ice crystals, thereby inhibiting their growth in the c direction and resulting in an increase in the effective supercooling with increasing fcIBP concentration. In addition, we observed that the fcIBP attaches to prism faces and inhibits their growth. In the event that the effective supercooling is small and crystals are faceted, this process causes an emergence of prism faces and suppresses crystal growth in the a direction. When the effective supercooling is large and ice crystals have developed into a dendritic shape, the suppression of prism face growth results in thinner dendrite branches, and growth in the a direction is accelerated due to enhanced latent heat dissipation. Our observations clearly indicate that the fcIBP occupies a separate position in the classification of IBPs due to the fact that it suppresses the growth of basal faces, despite its moderate freezing point depression.


2008 ◽  
Vol 8 (4) ◽  
pp. 13017-13042
Author(s):  
E. Fries ◽  
W. Haunold ◽  
E. Starokozhev ◽  
K. Palitzsch ◽  
R. Sitals ◽  
...  

Abstract. Both, gas and particle scavenging contribute to the transport of organic compounds by ice crystals in the troposphere. To simulate these processes an experimental setup was developed to form airborne ice crystals under atmospheric conditions. Experiments were performed in a wall independent reactor (WIR) installed in a walk-in cold chamber maintained constantly at −20°C. Aerosol particles were added to the carrier gas of ambient air by an aerosol generator to allow heterogeneous ice formation. Temperature variations and hydrodynamic conditions of the WIR were investigated to determine the conditions for ice crystal formation and crystal growth by vapour deposition. In detail, the dependence of temperature variations from flow rate and temperature of the physical wall as well as temperature variations with an increasing reactor depth were studied. The conditions to provide a stable aerosol concentration in the carrier gas flow were also studied. The temperature distribution inside the reactor was strongly dependent on flow rate and physical wall temperature. At an inlet temperature of −20°C, a flow rate of 30 L•min−1 and a physical wall temperature of +5°C turned out to provide ideal conditions for ice formation. At these conditions a sharp and stable laminar down draft "jet stream" of cold air in the centre of the reactor was produced. Temperatures measured at the chamber outlet were kept well below the freezing point in the whole reactor depth of 1.0 m. Thus, melting did not affect ice formation and crystal growth. The maximum residence time for airborne ice crystals was calculated to at 40 s. Ice crystal growth rates increased also with increasing reactor depth. The maximum ice crystal growth rate was calculated at 2.82 mg• s−1. Further, the removal efficiency of the cleaning device for aerosol particles was 99.8% after 10 min. A reliable particle supply was attained after a preliminary lead time of 15 min. Thus, the minimum lead time was determined at 25 min. Several test runs revealed that the WIR is suitable to perform experiments with airborne ice crystals.


Scientifica ◽  
2014 ◽  
Vol 2014 ◽  
pp. 1-20 ◽  
Author(s):  
Janet S. H. Lorv ◽  
David R. Rose ◽  
Bernard R. Glick

Across the world, many ice active bacteria utilize ice crystal controlling proteins for aid in freezing tolerance at subzero temperatures. Ice crystal controlling proteins include both antifreeze and ice nucleation proteins. Antifreeze proteins minimize freezing damage by inhibiting growth of large ice crystals, while ice nucleation proteins induce formation of embryonic ice crystals. Although both protein classes have differing functions, these proteins use the same ice binding mechanisms. Rather than direct binding, it is probable that these protein classes create an ice surface prior to ice crystal surface adsorption. Function is differentiated by molecular size of the protein. This paper reviews the similar and different aspects of bacterial antifreeze and ice nucleation proteins, the role of these proteins in freezing tolerance, prevalence of these proteins in psychrophiles, and current mechanisms of protein-ice interactions.


1979 ◽  
Vol 27 (11) ◽  
pp. 1520-1523 ◽  
Author(s):  
P M Frederik ◽  
W M Busing

Frozen thin sections and sections from freeze-dried and embedded tissue are used for the autoradiographic localization of diffusible substances at the electron microscope level. The presence of ice crystals in such sections may limit the autoradiographic resolution. Ice crystals are formed during freezing and may grow during subsequent processing of tissue. The contribution of ice crystal growth to the final image was estimated by measuring the distribution of the ice crystal sizes in freeze-etch replicas and in sections from freeze-dried and embedded tissues. A surface layer (10-15 mu) without visible ice crystals was present in both preparations. Beneath this surface layer the diameter of ice crystals increased towards the interior with the same relationship between crystal size and distance from the surface in the freeze-etch preparation as in the freeze-dry preparation. Ice crystal growth occurring during a much longer time during freeze-drying compared to freeze-etching does not significantly contribute to the final image in the electron microscope. The formation of ice crystals during freezing determines to a large extent the image (and therefore the autoradiographic resolution) of freeze-dry preparations and this probably holds also for thin cryosections of which examples are given.


2003 ◽  
Vol 37 ◽  
pp. 129-133 ◽  
Author(s):  
Karen Guldbæ K Schmidt ◽  
Dorthe Dahl-Jensen

AbstractA simple model for crystal growth in the ice shell of Europa has been made in order to estimate the size of ice crystals at Europa’s surface. If mass is lost from the surface of Europa due to sputtering processes, and the ice thickness is constant in time, ice crystals will be transported upwards in the ice shell. The crystals will therefore grow under varying conditions through the shell. The model predicts that ice crystals are 4 cm– 80 m across at the surface. For the preferred parameter values, a crystal size of the order of 7 m is calculated.


Volume 3 ◽  
2004 ◽  
Author(s):  
Z. M. Li ◽  
X. F. Peng

Frost formation on flat cold surfaces was experimentally investigated, particularly the dynamic process was visually observed. During test runs, a plastic film was used to separate the cold surface from moist air, and formation of ice crystals was observed using microscope visualization technique as the film was removed and the cold surface reached to a specified temperature. In crystal growth stage of frost formation, a new phenomenon was found during ice crystal growth process. A layer of irregular crystal embryos was formed at the earlier stage, and these crystal embryos vanished when ice crystals with regular form grew up along nicks on the plate. And then, ice crystals on the plate kept growing slowly, while the area without ice crystals kept clean. This process is divided into three stages: formation of crystal embryos, mutation of ice crystals, and growth of ice crystal. Duration times of the first two stages seemed to be constant for different cases.


Author(s):  
Jun Jie Liu ◽  
Yangzong Qin ◽  
Maya Bar Dolev ◽  
Yeliz Celik ◽  
J. S. Wettlaufer ◽  
...  

The melting of pure axisymmetric ice crystals has been described previously by us within the framework of so-called geometric crystal growth . Non-equilibrium ice crystal shapes evolving in the presence of hyperactive antifreeze proteins (hypAFPs) are experimentally observed to assume ellipsoidal geometries (‘lemon’ or ‘rice’ shapes). To analyse such shapes, we harness the underlying symmetry of hexagonal ice I h and extend two-dimensional geometric models to three-dimensions to reproduce the experimental dissolution process. The geometrical model developed will be useful as a quantitative test of the mechanisms of interaction between hypAFPs and ice.


2012 ◽  
Vol 24 (3) ◽  
pp. 259-268 ◽  
Author(s):  
Clive W. Evans ◽  
Linn Hellman ◽  
Martin Middleditch ◽  
Joanna M. Wojnar ◽  
Margaret A. Brimble ◽  
...  

AbstractEvolutionary disparate Antarctic notothenioids and Arctic gadids have adapted to their freezing environments through the elaboration of essentially identical antifreeze glycoproteins (AFGPs). Here we show that this convergence of molecular identity, which evolved from unrelated parent genes, extends to convergence in physiological deployment. Both fish groups synthesize AFGPs in the exocrine pancreas from where they are discharged into the gut to inhibit the growth of ingested ice. Antifreeze glycoproteins not lost with the faeces are resorbed from the gut via the rectal epithelium, transported to the blood and ultimately secreted into the bile, from where they re-enter the gastrointestinal tract. Antifreeze glycoprotein recirculation conserves energy expenditure and explains how high levels of AFGPs reach the blood in notothenioids since, unlike Arctic gadids which also synthesize AFGP in the liver, AFGP secretion in notothenioids is directed exclusively towards the gastrointestinal lumen. Since AFGPs function by inhibiting ice crystal growth, ice must be present for them to function. The two fish groups are thus faced with an identical problem of how to deal with internal ice. Here we show that both accumulate AFGPs within ellipsoidal macrophages of the spleen, presumably adsorbed to phagocytosed ice crystals which are then held until a warming event ensues.


Author(s):  
I. Taylor ◽  
P. Ingram ◽  
J.R. Sommer

In studying quick-frozen single intact skeletal muscle fibers for structural and microchemical alterations that occur milliseconds, and fractions thereof, after electrical stimulation, we have developed a method to compare, directly, ice crystal formation in freeze-substituted thin sections adjacent to all, and beneath the last, freeze-dried cryosections. We have observed images in the cryosections that to our knowledge have not been published heretofore (Figs.1-4). The main features are that isolated, sometimes large regions of the sections appear hazy and have much less contrast than adjacent regions. Sometimes within the hazy regions there are smaller areas that appear crinkled and have much more contrast. We have also observed that while the hazy areas remain still, the regions of higher contrast visibly contract in the beam, often causing tears in the sections that are clearly not caused by ice crystals (Fig.3, arrows).


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