Discovery of an antifreeze protein in the leaves of Ammopiptanthus nanus

2010 ◽  
Vol 90 (1) ◽  
pp. 35-40 ◽  
Author(s):  
S. Yu ◽  
L. Yin ◽  
S. Mu
Keyword(s):  
Differential Scanning Calorimetry ◽  
Thermal Hysteresis ◽  
Large Subunit ◽  
Antifreeze Proteins ◽  
Cold Climate ◽  
High Definition ◽  
Scanning Calorimetry ◽  
Bisphosphate Carboxylase ◽  
Thermal Hysteresis Activity ◽  
Ammopiptanthus Nanus

Overwintering plants produce antifreeze proteins (AFPs) that allow plants to survive under freezing or sub-freezing conditions. Ammopiptanthus nanus (M. Pop.) Cheng f. grows in the desert of Xinjiang, P.R. China, and our objective was to determine if its survival was dependent on AFP and to identify the protein. Using anion exchange and gel filtration, the AFP was extracted, isolated and purified from cold-acclimated A. nanus leaves. The thermal hysteresis activity (THA) of the antifreeze proteins was measured by differential scanning calorimetry. The THA of the AFP was 0.46°C when the concentration of the protein was 20 mg mL-1. The molecular weight of a band was about 119.24 kDa in SDS-PAGE gel. We detected (P < 0.05) the ribulose-1,5-bisphosphate carboxylase/oxygenase large subunit by analyzing the 119.24 kDa protein using the Waters SYNAPT™ high definition mass spectrometry (HDMS™) System. Our results indicate that there is an AFP in A. nanus leaves, and that it may play a vital role as a defence against the cold climate, thus increasing the chances for survival of A. nanus in its desert habitat.Key words: Thermal hysteresis activity, differential scanning calorimetry, extraction, purification, cold climate, desert habitat

scholarly journals Ice Growth Acceleration by Antifreeze Proteins Leads to Higher Thermal Hysteresis Activity

2020 ◽  
Author(s):  
Jinzi Deng ◽  
Elana Apfelbaum ◽  
Ran Drori
Keyword(s):  
Crystal Growth ◽  
Growth Inhibition ◽  
Growth Velocity ◽  
Crystal Morphology ◽  
Thermal Hysteresis ◽  
Antifreeze Proteins ◽  
Ice Crystal ◽  
Ice Growth ◽  
Thermal Hysteresis Activity ◽  
Adsorption Rates

<p>Since some antifreeze proteins and glycoproteins (AF(G)Ps) cannot directly bind to all crystal planes, they change ice crystal morphology by minimizing the area of the crystal planes to which they cannot bind until crystal growth is halted. Previous studies found that growth along the <i>c</i>-axis (perpendicular to the basal plane, the crystal plane to which these AF(G)Ps cannot bind) is accelerated by some AF(G)Ps, while growth of other planes is inhibited. The effects of this growth acceleration on crystal morphology and on the thermal hysteresis activity are unknown to date. Understanding these effects will elucidate the mechanism of ice growth inhibition by AF(G)Ps. Using cold stages and an Infrared laser, ice growth velocities and crystal morphologies in AF(G)P solutions were measured. Three types of effects on growth velocity were found: concentration-dependent acceleration, concentration-independent acceleration, and concentration-dependent deceleration. Quantitative crystal morphology measurements in AF(G)P solutions demonstrated that adsorption rate of the proteins to ice plays a major role in determining the morphology of the bipyramidal crystal. These results demonstrate that faster adsorption rates generate bipyramidal crystals with diminished basal surfaces at higher temperatures compared to slower adsorption rates. The acceleration of growth along the <i>c</i>-axis generates crystals with smaller basal surfaces at higher temperatures leading to increased growth inhibition of the entire crystal.<a></a></p>

Thermal Hysteresis in Ganglioside Micelles Investigated by Differential Scanning Calorimetry and Light-Scattering

Langmuir ◽  
1999 ◽  
Vol 15 (15) ◽  
pp. 4975-4980 ◽  
Author(s):  
Laura Cantú ◽  
Mario Corti ◽  
Elena Del Favero ◽  
Elke Muller ◽  
Antonio Raudino ◽  
...  
Keyword(s):  
Differential Scanning Calorimetry ◽  
Light Scattering ◽  
Thermal Hysteresis ◽  
Scanning Calorimetry

Experimental correlation between thermal hysteresis activity and the distance between antifreeze proteins on an ice surface

RSC Advances ◽  
2015 ◽  
Vol 5 (11) ◽  
pp. 7848-7853 ◽  
Author(s):  
Ran Drori ◽  
Peter L. Davies ◽  
Ido Braslavsky
Keyword(s):  
Fluorescence Microscopy ◽  
Thermal Hysteresis ◽  
Freezing Point ◽  
Antifreeze Proteins ◽  
Microfluidic Devices ◽  
Freezing Point Depression ◽  
Thermal Hysteresis Activity ◽  
Ice Surface ◽  
Experimental Correlation ◽  
Temperature Controlled

Temperature-controlled microfluidic devices and fluorescence microscopy illustrate the correlation between freezing-point depression and the distance between antifreeze proteins on an ice surface.

scholarly journals Ice Growth Acceleration by Antifreeze Proteins Leads to Higher Thermal Hysteresis Activity

2020 ◽  
Author(s):  
Jinzi Deng ◽  
Elana Apfelbaum ◽  
Ran Drori
Keyword(s):  
Crystal Growth ◽  
Growth Inhibition ◽  
Growth Velocity ◽  
Crystal Morphology ◽  
Thermal Hysteresis ◽  
Antifreeze Proteins ◽  
Ice Crystal ◽  
Ice Growth ◽  
Thermal Hysteresis Activity ◽  
Adsorption Rates

<p>Since some antifreeze proteins and glycoproteins (AF(G)Ps) cannot directly bind to all crystal planes, they change ice crystal morphology by minimizing the area of the crystal planes to which they cannot bind until crystal growth is halted. Previous studies found that growth along the <i>c</i>-axis (perpendicular to the basal plane, the crystal plane to which these AF(G)Ps cannot bind) is accelerated by some AF(G)Ps, while growth of other planes is inhibited. The effects of this growth acceleration on crystal morphology and on the thermal hysteresis activity are unknown to date. Understanding these effects will elucidate the mechanism of ice growth inhibition by AF(G)Ps. Using cold stages and an Infrared laser, ice growth velocities and crystal morphologies in AF(G)P solutions were measured. Three types of effects on growth velocity were found: concentration-dependent acceleration, concentration-independent acceleration, and concentration-dependent deceleration. Quantitative crystal morphology measurements in AF(G)P solutions demonstrated that adsorption rate of the proteins to ice plays a major role in determining the morphology of the bipyramidal crystal. These results demonstrate that faster adsorption rates generate bipyramidal crystals with diminished basal surfaces at higher temperatures compared to slower adsorption rates. The acceleration of growth along the <i>c</i>-axis generates crystals with smaller basal surfaces at higher temperatures leading to increased growth inhibition of the entire crystal.<a></a></p>

scholarly journals DSC Study on the Thermal Hysteresis Activity of Plant Antifreeze Proteins

2001 ◽  
Vol 17 (01) ◽  
pp. 66-69
Author(s):  
Zhou Xiao-Lei ◽  
◽  
Chen Tao-Tao ◽  
Wang Bao-Huai ◽  
Li Zhi-Fen ◽  
...  
Keyword(s):  
Thermal Hysteresis ◽  
Antifreeze Proteins ◽  
Thermal Hysteresis Activity ◽  
Plant Antifreeze Proteins

Thermal Stability of N-Heterocycle-Stabilized Iodanes – A Systematic Investigation

2019 ◽  
Author(s):  
Andreas Boelke ◽  
Yulia A. Vlasenko ◽  
Mekhman S. Yusubov ◽  
Boris Nachtsheim ◽  
Pavel Postnikov
Keyword(s):  
Thermal Stability ◽  
Differential Scanning Calorimetry ◽  
Thermogravimetric Analysis ◽  
Systematic Investigation ◽  
Scanning Calorimetry ◽  
Thermal Stability Of

<p>The thermal stability of pseudocyclic and cyclic <i>N</i>-heterocycle-stabilized (hydroxy)aryl- and mesityl(aryl)-l<sup>3</sup>-iodanes (NHIs) through thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) is investigated. NHIs bearing <i>N</i>-heterocycles with a high N/C-ratio such as triazoles show among the lowest descomposition temperatures and the highest decomposition energies. A comparison of NHIs with known (pseudo)cyclic benziodoxolones is made and we further correlated their thermal stability with reactivity in a model oxygenation. </p>

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