Unusual structural properties of water within the hydration shell of hyperactive antifreeze protein

2014 ◽  
Vol 141 (5) ◽  
pp. 055103 ◽  
Author(s):  
Anna Kuffel ◽  
Dariusz Czapiewski ◽  
Jan Zielkiewicz
Keyword(s):  
Structural Properties ◽  
Hydration Shell ◽  
Antifreeze Protein

scholarly journals A Molecular Dynamics Study of Aqueous Solutions. VIII. Improved Simulation and Structural Properties of a NH4Cl Solution

1979 ◽  
Vol 34 (7) ◽  
pp. 840-849 ◽  
Author(s):  
Gy. I. Szász ◽  
K. Heinzinger
Keyword(s):  
Molecular Dynamics ◽  
Structural Properties ◽  
Point Charge ◽  
Complex Structure ◽  
Hydration Shell ◽  
Orientational Order ◽  
Dynamics Simulation ◽  
Ammonium Ion ◽  
Point Charge Model ◽  
Charge Model

A molecular dynamics simulation of an aqueous ammonium chloride solution has been carried out at a mass density of 1.027 g/cm3, corresponding to a 2.2 m solution, and at a temperature of T = 301 K. The effective pair potentials are based on the ST2 model of water, a rigid tetra­hedral four point charge model of NH4+ and a single point charge model of Cl-. The calculated structural properties of this solution are discussed and compared with those obtained for alkali halide solutions. The first hydration shell of the ammonium ion contains on the average eight water molecules, it has a more complex structure than the hydration shells of cations with spherical symmetry. The static orientational order of water dipole moments indicate a structure breaking ability of NH4+.

scholarly journals Calcium-Binding Generates the Semi-Clathrate Waters on a Type II Antifreeze Protein to Adsorb onto an Ice Crystal Surface

Biomolecules ◽  
2019 ◽  
Vol 9 (5) ◽  
pp. 162 ◽  
Author(s):  
Tatsuya Arai ◽  
Yoshiyuki Nishimiya ◽  
Yasushi Ohyama ◽  
Hidemasa Kondo ◽  
Sakae Tsuda
Keyword(s):  
Binding Site ◽  
Calcium Binding ◽  
Crystal Surface ◽  
Hydration Shell ◽  
Antifreeze Protein ◽  
Bound State ◽  
Ice Crystal ◽  
Prism Plane ◽  
Ice Binding ◽  
Significant Difference

Hydration is crucial for a function and a ligand recognition of a protein. The hydration shell constructed on an antifreeze protein (AFP) contains many organized waters, through which AFP is thought to bind to specific ice crystal planes. For a Ca2+-dependent species of AFP, however, it has not been clarified how 1 mol of Ca2+-binding is related with the hydration and the ice-binding ability. Here we determined the X-ray crystal structure of a Ca2+-dependent AFP (jsAFP) from Japanese smelt, Hypomesus nipponensis, in both Ca2+-bound and -free states. Their overall structures were closely similar (Root mean square deviation (RMSD) of Cα = 0.31 Å), while they exhibited a significant difference around their Ca2+-binding site. Firstly, the side-chains of four of the five Ca2+-binding residues (Q92, D94 E99, D113, and D114) were oriented to be suitable for ice binding only in the Ca2+-bound state. Second, a Ca2+-binding loop consisting of a segment D94–E99 becomes less flexible by the Ca2+-binding. Third, the Ca2+-binding induces a generation of ice-like clathrate waters around the Ca2+-binding site, which show a perfect position-match to the waters constructing the first prism plane of a single ice crystal. These results suggest that generation of ice-like clathrate waters induced by Ca2+-binding enables the ice-binding of this protein.

Newborn's Preference for Faces

1996 ◽  
Vol 1 (3) ◽  
pp. 200-205 ◽  
Author(s):  
Carlo Umiltà ◽  
Francesca Simion ◽  
Eloisa Valenza
Keyword(s):  
Visual System ◽  
Structural Properties ◽  
Sensory Properties ◽  
Human Face ◽  
System Experiment ◽  
Face Experiment

Four experiments were aimed at elucidating some aspects of the preference for facelike patterns in newborns. Experiment 1 showed a preference for a stimulus whose components were located in the correct arrangement for a human face. Experiment 2 showed a preference for stimuli that had optimal sensory properties for the newborn visual system. Experiment 3 showed that babies directed their attention to a facelike pattern even when it was presented simultaneously with a non-facelike stimulus with optimal sensory properties. Experiment 4 showed the preference for facelike patterns in the temporal hemifield but not in the nasal hemifield. It was concluded that newborns' preference for facelike patterns reflects the activity of a subcortical system which is sensitive to the structural properties of the stimulus.

Investigation of the structural properties of crystallized Fe-(Cu)-Sm-B ribbons

1998 ◽  
Vol 08 (PR2) ◽  
pp. Pr2-47-Pr2-50
Author(s):  
O. Crisan ◽  
J. M. Le Breton ◽  
F. Machizaud ◽  
A. Jianu ◽  
J. Teillet ◽  
...  
Keyword(s):  
Structural Properties
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