RiAFP

From Proteopedia

(Difference between revisions)
Jump to: navigation, search
Line 17: Line 17:
[[Image:Fig2_C.jpg|frame|alt=Puzzle globe|Fig. 2. Hydrophobicity of RiAFP]]IBS is less hydrophilic than the other β–sheet, which is consistent with its role of interacting with the ice (see Figure 2). Adsorption of the AFP ice-binding surface to ice is facilitated by the flatness of the IBS of the AFP.The Sc (shape complementarity) values between RiAFP and ice interfaces range from 0.75-0.78, where 1.0 indicates perfect match. For comparison, antigen-antibody complexes usually have their Sc values in the range of 0.64–0.68.
[[Image:Fig2_C.jpg|frame|alt=Puzzle globe|Fig. 2. Hydrophobicity of RiAFP]]IBS is less hydrophilic than the other β–sheet, which is consistent with its role of interacting with the ice (see Figure 2). Adsorption of the AFP ice-binding surface to ice is facilitated by the flatness of the IBS of the AFP.The Sc (shape complementarity) values between RiAFP and ice interfaces range from 0.75-0.78, where 1.0 indicates perfect match. For comparison, antigen-antibody complexes usually have their Sc values in the range of 0.64–0.68.
[[Image:Fig5_A.jpg|frame|alt=Puzzle globe|Fig. 4. Docking of RiAFP to the primery prism plane of a hexagonal ice lattice]]Thr hydroxyls bind 3 ranks of 6 water molecules with equivalent spacing between the 4 ranks of Thr side chains. These water molecules are bound tightly, they have lost both translational and rotational freedom and resemble those in an ice lattice. The waters observed in the simulation appear to be organized in an ice-like formation, with close matches to the primary prism and basal planes of ice. IBS is responsible for ordering an ice-like array of anchored “clathrate” water molecules to promote adsorption to ice.(see Figure 4).
[[Image:Fig5_A.jpg|frame|alt=Puzzle globe|Fig. 4. Docking of RiAFP to the primery prism plane of a hexagonal ice lattice]]Thr hydroxyls bind 3 ranks of 6 water molecules with equivalent spacing between the 4 ranks of Thr side chains. These water molecules are bound tightly, they have lost both translational and rotational freedom and resemble those in an ice lattice. The waters observed in the simulation appear to be organized in an ice-like formation, with close matches to the primary prism and basal planes of ice. IBS is responsible for ordering an ice-like array of anchored “clathrate” water molecules to promote adsorption to ice.(see Figure 4).
 +
 +
An advantage of this indirect binding mechanism is that the organized waters are still fluid enough to make flexible matches to the ice-like quasi-liquid layer around the ice before becoming rigidified as the junction layer freezes. Alignment of IBS of RiAFP to hexagonal ice showed possible interactions of the protein with the several ice planes. Several ranks of matching Thr hydroxyls to water molecules give the RiAFP an ability to bind multiple ice planes, by that providing the protein hyperactivity(see Figure 5) .
 +
<scene name='60/607864/Isosurface/3'>Ice binding surface</scene>
<scene name='60/607864/Isosurface/3'>Ice binding surface</scene>

Revision as of 23:45, 24 January 2015

Insect antifreeze protein (PDB code 4dt5).

Drag the structure with the mouse to rotate

3D structures of antifreeze protein

Antifreeze protein

References

  1. Jia Z, Davies PL. Antifreeze proteins: an unusual receptor-ligand interaction. Trends Biochem Sci. 2002 Feb;27(2):101-6. PMID:11852248
  2. Chantelle J. Capicciotti, Malay Doshi and Robert N. Ben (2013). Ice Recrystallization Inhibitors: From Biological Antifreezes to Small Molecules, Recent Developments in the Study of Recrystallization, Prof. Peter Wilson (Ed.), ISBN: 978-953-51-0962-4, InTech doi:http://dx.doi.org/10.5772/54992
  3. Drori R, Celik Y, Davies PL, Braslavsky I. Ice-binding proteins that accumulate on different ice crystal planes produce distinct thermal hysteresis dynamics. J R Soc Interface. 2014 Sep 6;11(98):20140526. doi: 10.1098/rsif.2014.0526. PMID:25008081 doi:http://dx.doi.org/10.1098/rsif.2014.0526
  4. doi: https://dx.doi.org/10.1016/S0006-3495(91)82234-2
  5. Hakim A, Nguyen JB, Basu K, Zhu DF, Thakral D, Davies PL, Isaacs FJ, Modis Y, Meng W. Crystal structure of an insect antifreeze protein and its implications for ice binding. J Biol Chem. 2013 Apr 26;288(17):12295-304. doi: 10.1074/jbc.M113.450973. Epub, 2013 Mar 12. PMID:23486477 doi:10.1074/jbc.M113.450973

Proteopedia Page Contributors and Editors (what is this?)

Vera Sirotinskaya, Hila Cohen, Angel Herraez, Michal Harel

Personal tools