RiAFP
From Proteopedia
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Antifreeze proteins (AFPs) evolved in various organisms permitting their survival in subzero environments<ref>PMID: 11852248</ref>. They exhibit remarkable structural diversity and molar activities across the various kingdoms<ref>DOI 10.5772/54992</ref>. The longhorn beetle, Rhagium inquisitor, has the ability to supercool to below -25 °C partially due to the presence of a highly potent AFP (RiAFP) in its hemolymph. RiAFP is a 13-kDa protein with one of the highest antifreeze activities measured for any AFP. | Antifreeze proteins (AFPs) evolved in various organisms permitting their survival in subzero environments<ref>PMID: 11852248</ref>. They exhibit remarkable structural diversity and molar activities across the various kingdoms<ref>DOI 10.5772/54992</ref>. The longhorn beetle, Rhagium inquisitor, has the ability to supercool to below -25 °C partially due to the presence of a highly potent AFP (RiAFP) in its hemolymph. RiAFP is a 13-kDa protein with one of the highest antifreeze activities measured for any AFP. | ||
- | == | + | == Function == |
- | + | RiAFP, like other AFPs, adsorb to the surface of ice crystals and lower the temperature at which these crystals grow. Consequently, creating a difference between the melting point and the freezing point known as thermal hysteresis (TH), within which the ice growth is arrested<ref>DOI 10.1016/j.cryobiol.2013.09.150</ref>. | |
== Overall Structure == | == Overall Structure == | ||
The crystallographic structure of RiAFP was defined recently<ref>DOI 10.1074/jbc.M113.450973</ref>. RiAFP has a novel β-solenoid architecture that forms <scene name='60/607864/Beta_sheets/1'>β-sandwich</scene>. This sandwich is composed of two parallel remarkably regular <scene name='60/607864/Beta_sheets_colored/1'> 6 and 7 stranded-sheets</scene>. The β-sheets lie on top of each other with the upper and lower strands parallel but in the opposite orientation. Two ends deviate from β helix regularity by forming <scene name='60/607864/Beta_sheets_capping/2'>capping structures</scene>. These capping structures help to prevent end-to-end associations that would spoil the solubility of RiAFP and lead to oligomerization and aggregation. | The crystallographic structure of RiAFP was defined recently<ref>DOI 10.1074/jbc.M113.450973</ref>. RiAFP has a novel β-solenoid architecture that forms <scene name='60/607864/Beta_sheets/1'>β-sandwich</scene>. This sandwich is composed of two parallel remarkably regular <scene name='60/607864/Beta_sheets_colored/1'> 6 and 7 stranded-sheets</scene>. The β-sheets lie on top of each other with the upper and lower strands parallel but in the opposite orientation. Two ends deviate from β helix regularity by forming <scene name='60/607864/Beta_sheets_capping/2'>capping structures</scene>. These capping structures help to prevent end-to-end associations that would spoil the solubility of RiAFP and lead to oligomerization and aggregation. |
Revision as of 12:49, 22 January 2015
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3D structures of antifreeze protein
References
- ↑ Jia Z, Davies PL. Antifreeze proteins: an unusual receptor-ligand interaction. Trends Biochem Sci. 2002 Feb;27(2):101-6. PMID:11852248
- ↑ 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
- ↑ doi: https://dx.doi.org/10.1016/j.cryobiol.2013.09.150
- ↑ 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