講演会のお知らせ【2014.8.6】(2014.07.25更新)
| 演題 |
“Ice-Binding Proteins from Polar Microbes, Yeast and
Microalgae:Types, Functions, and Application”
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| 演者 | |
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| 所属 |
Department of Chemistry, Pukyong National University, Busan,Korea
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| 日時 | |
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| 場所 |
北海道大学理学部６号館６-１０３室
札幌市北区北10条西8丁目
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| 共催 | |
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| 概要 |
Ice-binding proteins (IBPs) are, literally, referred to a group of
proteins that bind to ice crystals. IBPs encompass antifreeze proteins
(AFPs), ice nucleation proteins (INPs), ice recrystallization protein,
and ice anchoring protein and so on. In most cases IBPs and AFPs are
interchangeable terms.
IBPs, although structurally diverse, bind to the surface of ice crystals
and control the growth of ice crystal growth. This binding causes
difference of melting and freezing points, termed thermal hysteresis
(TH) and ice recrystallization inhibition (RI). Extensive studies have
shown that IBPs from fish, insects, and plants are very effective in ice
RI. This ability seems to protect membranes from freezing injury and
thus to help the organisms survive at extremely cold environments.
We recently identified IBP from the Antarctic bacterium Flavobacterium
frigoris PS1 colonized in sea ice together with sea ice microalgae.
The X-ray crystal structure of FfIBP was determined to 2.1 Å resolution
to gain insight into its ice binding mechanism. The refined structure of
FfIBP shows an intramolecular disulfide bond, and analytical
ultracentrifugation and analytical size-exclusion chromatography show
that it behaves as a monomer in solution. Although FfIBP closely
resembles previously characterized Leucosporidium (recently
re-classified as Glaciozyma) IBP (LeIBP) in its
amino-acid sequence, the thermal hysteresis (TH) activity of FfIBP
appears to be tenfold higher than that of LeIBP.
Here we present characterization, structural determination, and
application of marine bacterial IBP and its comparison with closely
related LeIBP.
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| 連絡先 | |
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関連資料
Dr. Hak Jun Kim 講演会 ポスター【PDF】（117KB）
