RiAFP: Difference between revisions
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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. | ||
