2024-03-29T05:43:11Zhttps://eprints.lib.hokudai.ac.jp/dspace-oai/requestoai:eprints.lib.hokudai.ac.jp:2115/654332022-11-17T02:08:08Zhdl_2115_20055hdl_2115_8527Concentration-dependent oligomerization of an alpha-helical antifreeze polypeptide makes it hyperactiveMahatabuddin, SheikhHanada, YuichiNishimiya, YoshiyukiMiura, AiKondo, HidemasaDavies, Peter L.1000070211381Tsuda, Sakaeopen accessCreative Commons Attribution 4.0 International460A supersoluble 40-residue type I antifreeze protein (AFP) was discovered in a righteye flounder, the barfin plaice (bp). Unlike all other AFPs characterized to date, bpAFP transitions from moderately-active to hyperactive with increasing concentration. At sub-mM concentrations, bpAFP bound to pyramidal planes of ice to shape it into a bi-pyramidal hexagonal trapezohedron, similarly to the other moderately-active AFPs. At sub-mM concentrations, bpAFP uniquely underwent further binding to the whole ice crystal surface including the basal planes. The latter caused a bursting ice crystal growth normal to c-axis, 3 degrees C of high thermal hysteresis, and alteration of an ice crystal into a smaller lemon-shaped morphology, all of which are well-known properties of hyperactive AFPs. Analytical ultracentrifugation showed this activity transition is associated with oligomerization to form tetramer, which might be the forerunner of a naturally occurring four-helix-bundle AFP in other flounders.Nature Publishing Group2017-02-13engjournal articleVoRhttp://hdl.handle.net/2115/65433https://doi.org/10.1038/srep425012045-2322Scientific reports742501https://eprints.lib.hokudai.ac.jp/dspace/bitstream/2115/65433/2/Supplementary%20Information.pdfapplication/pdf889.92 KB2017-02-13https://eprints.lib.hokudai.ac.jp/dspace/bitstream/2115/65433/1/srep42501.pdfapplication/pdf1.16 MB2017-02-13