• KSBB Journal
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• 제28권5호
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• pp.310-314
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• 2013

Antifreeze peptide from Myoxocephalus octodecemspinosus was overexpressed and purified in Escherichia coli. Green fluorescence protein-AFP chimera was constructed by integrating gfp and afp genes. Produced GFP-AFP chimera protein was purified using polyhistidine tag which was inserted at C-terminus. By addition of GFP-AFP chimera protein, freezing point of elution buffer was decreased from $-13^{\circ}C$ to $-20^{\circ}C$. This result suggested that GFP-AFP chimera can be considered as a potential candidate of novel inhibitor for gas hydrates.

• 한국기계가공학회지
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• 제15권5호
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• pp.117-124
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• 2016

In this paper, we developed a breather valve with a water mist system for use near an oil storage tank. Our process applied a water mist system to the flame arrester to evaluate the fire suppression characteristics. For the fire suppression evaluation of the water mist system, we evaluated the angle of the nozzle, fire suppression, spray particle size, flashback, fire suppression time, and fire suppression test of antifreeze. Through the fire suppression test, the best fire suppression nozzle used an angle of $140^{\circ}$, and the flashback phenomenon of flame arrester did not occur. The fire suppression time of water mist system time was within three seconds, and the antifreeze was no problem with the fire suppression.

• Bulletin of the Korean Chemical Society
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• 제33권7호
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• pp.2411-2414
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• 2012

• 한국육종학회지
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• 제40권3호
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• pp.234-242
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• 2008

To identify low temperature-induced genes of wheat chromosome substitution line 5D, suppression subtractive hybridization (SSH) was performed with mRNAs from leaf samples that treated with low temperature ($4^{\circ}C$). A cDNA library was constructed using mRNA isolated from wheat chromosome substitution line 5D leaves treated with low temperature ($4^{\circ}C$). The nucleotide and deduced amino acid sequences of the putative gene products were compared. wfr-9 and wfr-32 showed identity over 90% related to vernalization gene. Other two genes, wfr-77 and wfr-83 which is related to freezing-resistant gene have also identity over 90%. This result suggest that those genes may be transcribed into antifreeze proteins which are accumulated within leaf apoplasts, when wheat chromosome substitution line 5D is acclimated during low temperature treatment.

• 한국작물학회:학술대회논문집
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• 한국작물학회 1998년도 춘계 학술대회지
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• pp.195-196
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• 1998

• KSBB Journal
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• 제30권6호
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• pp.345-349
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• 2015

Antifreeze proteins (AFP) inhibit growth and recrystallization of ice, and permit organisms to survive in cold environments. The AFP from an Antarctic bacterium, Flavobacterium frigoris PS1, FfIBP (Flavobacterium frigoris icebinding protein), was produced in E. coli using a cold shock induction system. The culture temperature was shifted from $37^{\circ}C$ to $15^{\circ}C$ and a 20 L culture scale was used. The final weights of dried cell and FfIBP were estimated to be 126 g and 8.4 g, respectively. The thermal hysteresis (TH) activity ($1.53^{\circ}C$) of the produced FfIBP was 3.6-fold higher than that of the LeIBP (Leucosporidium ice-binding protein) produced in Picha. The current study demonstrates that large-scale production of FfIBP was successful and the result could be extended to further application studies using recombinant AFPs.

• 식물조직배양학회지
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• 제22권1호
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• pp.15-28
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• 1995

보리의 내동성기작에 관여할 것으로 예상되는 반결빙단백질을 분리하기 위해서 저온순화기간 중에 세포밖 공간에 축적되는 단백질을 분리 및 비교하였다. 42일간의 저온처리를 통해 70, 21, 16, 14 KDa의 단백질과 10 KDa 이하의 연속된 크기의 단백질들의 축적이 증가됨을 확인하였다. 이들 단백질들은 3일간의 저온처리에서도 어느 정도 축적되었으나, 42일간의 처리시 그 양에 있어서 더욱 증가됨을 볼 수 있었다. 위 방법으로 얻어진 단백질을 전체 잎조직의 단백질과 비교하여 세포밖 공간의 단백질 추출방법의 정확도를 검증하였다. 또한 호밀의 저온처리시 세포밖 공간에 축적하는 단백질과의 비교를 통해 구성 단백질의 크기에 있어서 차이를 확인하였으나, 호밀과 보리에서 공통적으로 10 KDa 이하의 범위에서 연속적인 크기의 단백질이 축적됨을 볼 수 있었다. 알려진 광어의 반결빙단백질은 크기가 3300에서 33,000 dalton에 이르는 점으로 미루어 보리와 호밀에서 공통적으로 발견되는 10 KDa 이하의 단백질이 반결빙단백질로 작용할 가능성은 매우 높다. Griffith등(1992)은 호밀의 세포밖 공간 단백질중 일부에서 반결빙활성도를 확인하였고 보리와 호밀간의 해당단백질의 전체적인 profile에서의 유사성을 미루어 보리로부터 얻어진 세포밖 공간의 단백질에서 반결빙단백질을 발견할 가능성은 매우 높다.

• 한국수정란이식학회지
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• 제31권4호
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• pp.355-365
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• 2016

The cryopreservation of sperm has become the subject of research for successful artificial insemination technologies. Antifreeze proteins (AFPs), one of the factors necessary for effective cryopreservation, are derived from certain Antarctic organisms. These proteins decrease the freezing point of water within these organisms to below the temperature of the surrounding seawater to protect the organism from cold shock. Accordingly, a recent study found that AFPs can increase the motility and viability of spermatozoa during cryopreservation. To evaluate this relationship, we performed cryopreservation of boar sperm with AFPs produced in the Arctic yeast Leucosporidium sp. AFP expression system at four concentrations (0, 0.01, 0.1, and $1{\mu}g/ml$) and evaluated motility using computer assisted sperm analysis. DNA damage to boar spermatozoa was measured by the comet assay, and sperm membrane integrity and acrosome integrity were evaluated by flow cytometry. The results showed that motility was positively affected by the addition of AFP at each concentration except $1{\mu}g/ml$ (p<0.001). Although cryopreservation with AFP decreased the viability of the boar sperm using, the tail DNA analyses showed that there was no significant difference between the control and the addition of 0.1 or $0.01{\mu}g/ml$ AFP. In addition, the percentage of live sperm with intact acrosomes showed the least significant difference between the control and $0.1{\mu}g/ml$ AFP (p<0.05), but increased with $1{\mu}g/ml$ AFP (p<0.001). Our results indicate that the addition of AFP during boar sperm cryopreservation can improve viability and acrosome integrity after thawing.

• KSBB Journal
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• 제29권4호
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• pp.303-306
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• 2014

Antifreeze proteins (AFP) inhibit ice growth to permit the survival of polar organisms in the cold environments. The recombinant AFP from an Antarctic bacterium, Flavobacterium frigoris PS1, FfIBP (Flavobacterium frigoris ice-binding protein), was produced using Pichia pastoris expression system. The optimum fermentation temperature ($30^{\circ}C$) and pH (5) for FfIBP production were determined using a fed-batch culture system. The maximal cell density and purified FfIBP were 112 g/L and 70 mg/L, respectively. The thermal hysteresis (TH) activity (0.85) of FfIBP obtained using a glycerol-methanol fed-batch culture system was 2-fold higher than that of the LeIBP (Leucosporidium ice-binding protein). This work allows for large-scale production of FfIBP, which could be extended to further application studies using recombinant AFPs.

• 한국산학기술학회논문지
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• 제19권4호
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• pp.1-7
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• 2018

화석연료를 사용하는 내연기관에서 배출되는 가스는 환경오염, 지구온난화와 인체에 유해하여 많은 사회적인 문제를 야기시키고 있다. 최근에는 신재생에너지의 수요가 증가하고 있으며, 정부의 정책적인 지원과 연구개발 또한 활발하다. 가정에서 많이 사용되는 태양열에너지 시스템의 집열부는 열매체로 프로필렌글리콜 부동액이 물과 50% 고정된 값으로 혼합되어 영하온도에서도 집열부에 열을 전달한다. 그러나 집열부 내의 열매체에 누수가 발생되면 태양열시스템 특성상 보충수를 태양열 집열부에 공급하는데, 이로 인하여 보충수 내의 급수로 인하여 부동액 농도가 낮아지게 된다. 이에 따라 태양열 집열부위의 온도가 저하되어 동파를 야기하게 되는데 태양열에너지 시스템 정비 보수를 위해서 비용 부담이 증가하여 많은 문제점을 증가시킨다. 이 연구는 태양열에너지 시스템에 발생되는 동파 방지를 위하여 온도 저하에 따라 자동으로 부동액 농도를 제어가능한 장치를 개발하는 것이다. 물 성분이 프로필렌글리콜보다 전기전도도가 크며, 온도가 저온으로 내려갈수록 저항값이 증가하였다. 프로필렌글리콜 농도 제어 목표값 40, 50 및 60% 값은 39.6, 50.7 및 60.1%의 프로필렌글리콜 농도값으로 보정을 통하여 제어를 해야 한다.