title: Biophysical characterization of soluble Pseudomonas syringae ice nucleation protein InaZ fragments.
abstract: Ice nucleation protein (INP) with its functional domain consisting of multiple 48-residue repeat units effectively induces super-cooled water into ice. Circular dichroism and infrared deconvolution analyses on a soluble 240-residue fragment of Pseudomonas syringae InaZ (InaZ240) containing five 48-residue repeat units indicated that it is mostly composed of β-sheet and random coil. Analytical ultracentrifugation suggested that InaZ240 behaves as a monomer of an elongated ellipsoid. However, InaZ240 showed only minimum ice binding compared to anti-freeze proteins. Other P. syringae InaZ proteins with more 48-residue repeat units were made, in which the largest soluble fragment obtainable was an InaZ with twelve 48-residue repeat units. Size-exclusion chromatography analyses further suggested that the overall shape of the expressed InaZ fragments is pH-dependent, which becomes compact as the numbers of 48-residue repeat unit increase.
authors: School of Systems Biomedical Science, Soongsil University, Seoul 06978, Republic of Korea.
authors: Yu Jin
authors: YJ
authors: Han
authors: School of Systems Biomedical Science, Soongsil University, Seoul 06978, Republic of Korea.
authors: HyoJin
authors: H
authors: Song
authors: Division of Polar Life Sciences, Korea Polar Research Institute, Incheon 21990, Republic of Korea; Department of Polar Sciences, Korea University of Science and Technology, Incheon 21990, Republic of Korea.
authors: Chang Woo
authors: CW
authors: Lee
authors: Department of Chemistry, Soongsil University, Seoul 06978, Republic of Korea.
authors: Nguyễn Hoàng
authors: NH
authors: Ly
authors: Department of Chemistry, Soongsil University, Seoul 06978, Republic of Korea.
authors: Sang-Woo
authors: SW
authors: Joo
authors: Division of Polar Life Sciences, Korea Polar Research Institute, Incheon 21990, Republic of Korea; Department of Polar Sciences, Korea University of Science and Technology, Incheon 21990, Republic of Korea.
authors: Jun Hyuck
authors: JH
authors: Lee
authors: Department of Chemistry, Mokpo National University, Muan 58554, Republic of Korea.
authors: Soon-Jong
authors: SJ
authors: Kim
authors: School of Systems Biomedical Science, Soongsil University, Seoul 06978, Republic of Korea. Electronic address: psy@ssu.ac.kr.
authors: SangYoun
authors: S
authors: Park
mesh_terms: D001425:Bacterial Outer Membrane Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D003001:Cloning, Molecular; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism; D015870:Gene Expression; D006863:Hydrogen-Ion Concentration; D007053:Ice / Q000032:analysis*; D010446:Peptide Fragments / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D000072757:Protein Conformation, beta-Strand; D000072417:Protein Domains; D044224:Pseudomonas syringae / Q000737:chemistry*; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D012995:Solubility; D014461:Ultracentrifugation
chemical_list: D001425:Bacterial Outer Membrane Proteins; D007053:Ice; D010446:Peptide Fragments; D011994:Recombinant Proteins; C063113:ice nucleation protein
keywords: Bacterial ice nuclei; Ice nucleation protein; InaZ; Pseudomonas syringae