| Structural highlights
Function
IBP_LEUSY Confers freeze tolerance. Binds to the surface of ice crystals and inhibits their growth. Has low thermal hysteresis (TH) activity, which is the ability to lower the freezing point of an aqueous solution below its melting point (PubMed:20067781, PubMed:22303017, PubMed:22426061, PubMed:22622645, PubMed:23203635, PubMed:24699650). The TH activity of this protein is approximately 0.2 degrees Celsius at 50 uM and 0.3 degrees Celsius at 400 uM (PubMed:24699650).[1] [2] [3] [4] [5] [6]
Publication Abstract from PubMed
Arctic yeast Leucosporidium sp. produces a glycosylated ice-binding protein (LeIBP) with a molecular mass of approximately 25 kDa, which can lower the freezing point below the melting point once it binds to ice. LeIBP is a member of a large class of ice-binding proteins, the structures of which are unknown. Here, we report the crystal structures of non-glycosylated LeIBP and glycosylated LeIBP at 1.57 A and 2.43 A resolution, respectively. Structural analysis of the LeIBPs revealed a dimeric right-handed beta-helix fold, which is composed of three parts: a large coiled structural domain, a long helix region (residues 96-115 form a long alpha-helix that packs along one face of the beta-helix) and a C-terminal hydrophobic loop region (243-PFVPAPEVV-251). Unexpectedly, the C-terminal hydrophobic loop region has an extended conformation pointing away from the body of the coiled structural domain and forms intertwined dimer interactions. In addition, structural analysis of glycosylated LeIBP with sugar moieties attached to Asn185 provides a basis for interpreting previous biochemical analyses as well as the increased stability and secretion of glycosylated LeIBP. We also determined that the aligned Thr/Ser/Ala residues are critical for ice binding within the B face of LeIBP using site-directed mutagenesis. Although LeIBP has a common beta-helical fold similar to that of canonical hyperactive antifreeze proteins, the ice-binding site is more complex and does not have a simple ice-binding motif. In conclusion, we could identify the ice-binding site of LeIBP and discuss differences in the ice-binding modes compared to other known AFPs and IBPs.
Structural basis for the antifreeze activity of an ice-binding protein from an Arctic yeast.,Lee JH, Park AK, Do H, Park KS, Moh SH, Chi YM, Kim HJ J Biol Chem. 2012 Feb 2. PMID:22303017[7]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
See Also
References
- ↑ Lee JK, Park KS, Park S, Park H, Song YH, Kang SH, Kim HJ. An extracellular ice-binding glycoprotein from an Arctic psychrophilic yeast. Cryobiology. 2010 Apr;60(2):222-8. PMID:20067781 doi:10.1016/j.cryobiol.2010.01.002
- ↑ Lee JH, Park AK, Do H, Park KS, Moh SH, Chi YM, Kim HJ. Structural basis for the antifreeze activity of an ice-binding protein from an Arctic yeast. J Biol Chem. 2012 Feb 2. PMID:22303017 doi:10.1074/jbc.M111.331835
- ↑ Park KS, Do H, Lee JH, Park SI, Kim Ej, Kim SJ, Kang SH, Kim HJ. Characterization of the ice-binding protein from Arctic yeast Leucosporidium sp. AY30. Cryobiology. 2012 Jun;64(3):286-96. PMID:22426061 doi:10.1016/j.cryobiol.2012.02.014
- ↑ Lee SG, Koh HY, Lee JH, Kang SH, Kim HJ. Cryopreservative effects of the recombinant ice-binding protein from the arctic yeast Leucosporidium sp. on red blood cells. Appl Biochem Biotechnol. 2012 Jun;167(4):824-34. PMID:22622645 doi:10.1007/s12010-012-9739-z
- ↑ Lee JH, Lee SG, Do H, Park JC, Kim E, Choe YH, Han SJ, Kim HJ. Optimization of the pilot-scale production of an ice-binding protein by fed-batch culture of Pichia pastoris. Appl Microbiol Biotechnol. 2013 Apr;97(8):3383-93. PMID:23203635 doi:10.1007/s00253-012-4594-y
- ↑ Do H, Kim SJ, Kim HJ, Lee JH. Structure-based characterization and antifreeze properties of a hyperactive ice-binding protein from the Antarctic bacterium Flavobacterium frigoris PS1. Acta Crystallogr D Biol Crystallogr. 2014 Apr 1;70(Pt 4):1061-73. doi:, 10.1107/S1399004714000996. Epub 2014 Mar 19. PMID:24699650 doi:http://dx.doi.org/10.1107/S1399004714000996
- ↑ Lee JH, Park AK, Do H, Park KS, Moh SH, Chi YM, Kim HJ. Structural basis for the antifreeze activity of an ice-binding protein from an Arctic yeast. J Biol Chem. 2012 Feb 2. PMID:22303017 doi:10.1074/jbc.M111.331835
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