Biophysical characterization of soluble Pseudomonas syringae ice nucleation protein InaZ fragments

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• 作者：Yu Jin Han^a ; ¹ ; HyoJin Song^a ; ¹ ; Chang Woo Lee^b ; ^c ; Nguyễn Hoà ; ng Ly^d ; Sang-Woo Joo^d ; Jun Hyuck Lee^b ; ^c ; Soon-Jong Kim^e ; SangYoun Park^a ; ^{psy@ssu.ac.kr}
• 关键词：AUC ; analytical ultracentrifugation ; AFP ; anti-freeze protein ; CD ; circular dichroism ; FPLC ; fast protein liquid chromatography ; INP ; ice nucleation protein ; IR ; infrared ; LeIBP ; Leucosporidium ice-binding protein ; Ni-NTA ; Ni2+-nitrilotriacetic acid ; NMR ; nuclear magnetic resonance ; RMS ; root-mean-square ; RPM ; rotation per minute ; SDS-PAGE ; sodium dodecyl sulfate-polyacrylamide gel electrophoresis ; SEC ; size-exclusion chromatography
• 刊名：International Journal of Biological Macromolecules
• 出版年：2017
• 出版时间：January 2017
• 年：2017
• 卷：94
• 期：part_PA
• 页码：634-641
• 全文大小：2067 K
• 卷排序：94

文摘

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.