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Creating Anti-icing Surfaces via the Direct Immobilization of Antifreeze Proteins on Aluminum.

Gwak Y, Park JI, Kim M, Kim HS, Kwon MJ, Oh SJ, Kim YP, Jin E - Sci Rep (2015)

Bottom Line: The ABP bound well to the Al and did not considerably change the functional properties of AFP.Additional trehalose coating of Cn-AFP-Al considerably delayed AFP denaturation on the Al without affecting its antifreeze activity.This metal surface-coating method using trehalose-fortified AFP can be applied to other metals important in the aircraft and cold storage fields where anti-icing materials are critical.

View Article: PubMed Central - PubMed

Affiliation: Department of Life Science, Research Institute for Natural Science, Hanyang University, Seoul, 133-791, South Korea.

ABSTRACT
Cryoprotectants such as antifreeze proteins (AFPs) and sugar molecules may provide a solution for icing problems. These anti-icing substances protect cells and tissues from freezing by inhibiting ice formation. In this study, we developed a method for coating an industrial metal material (aluminum, Al) with AFP from the Antarctic marine diatom, Chaetoceros neogracile (Cn-AFP), to prevent or delay ice formation. To coat Al with Cn-AFP, we used an Al-binding peptide (ABP) as a conjugator and fused it with Cn-AFP. The ABP bound well to the Al and did not considerably change the functional properties of AFP. Cn-AFP-coated Al (Cn-AFP-Al) showed a sufficiently low supercooling point. Additional trehalose coating of Cn-AFP-Al considerably delayed AFP denaturation on the Al without affecting its antifreeze activity. This metal surface-coating method using trehalose-fortified AFP can be applied to other metals important in the aircraft and cold storage fields where anti-icing materials are critical.

No MeSH data available.


Related in: MedlinePlus

Secondary trehalose coating of ABP-Cn-AFPG124Y on an Al plate.(A) Schematic diagram of trehalose coating procedure. (B) The TMB assay, six days after coating, the proteins were denatured in the absence of trehalose coating. Secondary trehalose coating preserved the protein structure. (C) Spectrophotometry of the TMB solutions. Without trehalose coating, proteins on the Al plate were denatured after 6 days. In the presence of trehalose coating, the protein was still not denatured twelve days after coating. Asterisks (* and **) denote statistical significance of the differences in colorimetric intensity of surface-immobilized ABP-Cn-AFPG124Y with and without trehalose over the time course (p < 0.01, paired t-test, n = 4). Error bars indicate standard deviation.
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f5: Secondary trehalose coating of ABP-Cn-AFPG124Y on an Al plate.(A) Schematic diagram of trehalose coating procedure. (B) The TMB assay, six days after coating, the proteins were denatured in the absence of trehalose coating. Secondary trehalose coating preserved the protein structure. (C) Spectrophotometry of the TMB solutions. Without trehalose coating, proteins on the Al plate were denatured after 6 days. In the presence of trehalose coating, the protein was still not denatured twelve days after coating. Asterisks (* and **) denote statistical significance of the differences in colorimetric intensity of surface-immobilized ABP-Cn-AFPG124Y with and without trehalose over the time course (p < 0.01, paired t-test, n = 4). Error bars indicate standard deviation.

Mentions: Despite successful immobilization, denaturing of the AFP on the Al surface may reduce its antifreeze ability. To gain insight into AFP denaturation, we examined the stability of surface-immobilized Cn-AFP over time using the HRP/TMB colorimetric assay. We employed the trehalose-coating method to prevent protein denaturation, because trehalose is reported to make proteins resistant to dehydration when dried. Protein conformation can be preserved during drying through the hydrogen-bonded interaction of trehalose and water molecules, which efficiently competes with the interaction between protein and water molecules inside a trehalose-entrapped network25. As depicted in Fig. 5A, trehalose treatment on AFP-immobilized-on-Al surfaces was performed by incubating the surfaces in a trehalose-loaded solution for 1 h. When the ABP-Cn-AFPG124Y was incubated at room temperature for up to 12 days after immobilization on Al, its denaturation was monitored via colorimetric analysis; the surface not treated with trehalose showed a rapid reduction in color (left panel in Fig. 5B and black bar in Fig. 5C). The colorimetric signal gradually decreased and the coloration declined to 34% at day 12, compared to the initial signal intensity at day 0 (Fig. 5B). It is likely that the His6-tagged regions of ABP-Cn-AFPs are susceptible to a rapid conformational change upon binding to Al, probably due to protein denaturation on the Al surface. Mass spectrometric surface analysis of amino acids revealed that histidine-rich regions of both ABP-Cn-AFPs disappeared after 30 days on the Al surface (data not shown). In contrast, color remained stable in the presence of trehalose over the tested time period (right panel in Fig. 5B and white bar in Fig. 5C). This result suggests that trehalose coating effectively inhibits AFP denaturation on the Al surface, and this method may be suitable for preserving the activity of surface-immobilized AFPs.


Creating Anti-icing Surfaces via the Direct Immobilization of Antifreeze Proteins on Aluminum.

Gwak Y, Park JI, Kim M, Kim HS, Kwon MJ, Oh SJ, Kim YP, Jin E - Sci Rep (2015)

Secondary trehalose coating of ABP-Cn-AFPG124Y on an Al plate.(A) Schematic diagram of trehalose coating procedure. (B) The TMB assay, six days after coating, the proteins were denatured in the absence of trehalose coating. Secondary trehalose coating preserved the protein structure. (C) Spectrophotometry of the TMB solutions. Without trehalose coating, proteins on the Al plate were denatured after 6 days. In the presence of trehalose coating, the protein was still not denatured twelve days after coating. Asterisks (* and **) denote statistical significance of the differences in colorimetric intensity of surface-immobilized ABP-Cn-AFPG124Y with and without trehalose over the time course (p < 0.01, paired t-test, n = 4). Error bars indicate standard deviation.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4495550&req=5

f5: Secondary trehalose coating of ABP-Cn-AFPG124Y on an Al plate.(A) Schematic diagram of trehalose coating procedure. (B) The TMB assay, six days after coating, the proteins were denatured in the absence of trehalose coating. Secondary trehalose coating preserved the protein structure. (C) Spectrophotometry of the TMB solutions. Without trehalose coating, proteins on the Al plate were denatured after 6 days. In the presence of trehalose coating, the protein was still not denatured twelve days after coating. Asterisks (* and **) denote statistical significance of the differences in colorimetric intensity of surface-immobilized ABP-Cn-AFPG124Y with and without trehalose over the time course (p < 0.01, paired t-test, n = 4). Error bars indicate standard deviation.
Mentions: Despite successful immobilization, denaturing of the AFP on the Al surface may reduce its antifreeze ability. To gain insight into AFP denaturation, we examined the stability of surface-immobilized Cn-AFP over time using the HRP/TMB colorimetric assay. We employed the trehalose-coating method to prevent protein denaturation, because trehalose is reported to make proteins resistant to dehydration when dried. Protein conformation can be preserved during drying through the hydrogen-bonded interaction of trehalose and water molecules, which efficiently competes with the interaction between protein and water molecules inside a trehalose-entrapped network25. As depicted in Fig. 5A, trehalose treatment on AFP-immobilized-on-Al surfaces was performed by incubating the surfaces in a trehalose-loaded solution for 1 h. When the ABP-Cn-AFPG124Y was incubated at room temperature for up to 12 days after immobilization on Al, its denaturation was monitored via colorimetric analysis; the surface not treated with trehalose showed a rapid reduction in color (left panel in Fig. 5B and black bar in Fig. 5C). The colorimetric signal gradually decreased and the coloration declined to 34% at day 12, compared to the initial signal intensity at day 0 (Fig. 5B). It is likely that the His6-tagged regions of ABP-Cn-AFPs are susceptible to a rapid conformational change upon binding to Al, probably due to protein denaturation on the Al surface. Mass spectrometric surface analysis of amino acids revealed that histidine-rich regions of both ABP-Cn-AFPs disappeared after 30 days on the Al surface (data not shown). In contrast, color remained stable in the presence of trehalose over the tested time period (right panel in Fig. 5B and white bar in Fig. 5C). This result suggests that trehalose coating effectively inhibits AFP denaturation on the Al surface, and this method may be suitable for preserving the activity of surface-immobilized AFPs.

Bottom Line: The ABP bound well to the Al and did not considerably change the functional properties of AFP.Additional trehalose coating of Cn-AFP-Al considerably delayed AFP denaturation on the Al without affecting its antifreeze activity.This metal surface-coating method using trehalose-fortified AFP can be applied to other metals important in the aircraft and cold storage fields where anti-icing materials are critical.

View Article: PubMed Central - PubMed

Affiliation: Department of Life Science, Research Institute for Natural Science, Hanyang University, Seoul, 133-791, South Korea.

ABSTRACT
Cryoprotectants such as antifreeze proteins (AFPs) and sugar molecules may provide a solution for icing problems. These anti-icing substances protect cells and tissues from freezing by inhibiting ice formation. In this study, we developed a method for coating an industrial metal material (aluminum, Al) with AFP from the Antarctic marine diatom, Chaetoceros neogracile (Cn-AFP), to prevent or delay ice formation. To coat Al with Cn-AFP, we used an Al-binding peptide (ABP) as a conjugator and fused it with Cn-AFP. The ABP bound well to the Al and did not considerably change the functional properties of AFP. Cn-AFP-coated Al (Cn-AFP-Al) showed a sufficiently low supercooling point. Additional trehalose coating of Cn-AFP-Al considerably delayed AFP denaturation on the Al without affecting its antifreeze activity. This metal surface-coating method using trehalose-fortified AFP can be applied to other metals important in the aircraft and cold storage fields where anti-icing materials are critical.

No MeSH data available.


Related in: MedlinePlus