• Journal of Microbiology and Biotechnology
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• 제15권2호
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• pp.254-258
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• 2005

We have conducted in vitro reconstitution study of ferritin from its subunits FerH and FerL. For the reconstitution, FerH was produced from an expression vector construct in Escherichia coli and was purified from a heat treated cell extract by using one-step column chromatography. FerL was expressed as inclusion bodies. The denatured form of FerL was obtained by a simple washing step of the inclusion bodies with 3 M urea. The reconstitution experiment was conducted with various molar ratios of urea-denatured FerH and FerL to make the ferritin nanoparticle with a controlled composition of FerH and FerL. SDS-PAGE analysis of the reconstituted ferritins revealed that the reconstitution required the presence of more than 40 molar$\%$ of FerH in the reconstitution mixture. The assembly of the subunits into the ferritin nanoparticle was confmned by the presence of spherical particles with diameter of 10 nm by the atomic force microscopic image. Further analysis of the particles by using a transmission electron microscope revealed that the reconstituted particles exhibited different percentages of population with dense iron core. The reconstituted ferritin nanoparticles made with molar ratios of [FerH]/[FerL]=l00/0 and 60/40 showed that 80 to $90\%$ of the particles were apoferritin, devoid of iron core. On the contrary, all the particles formed with [FerH]/[FerL]=85/ 15 were found to contain the iron core. This suggests that although FerH can uptake iron, a minor portion of FerL, not exceeding $40\%$ at most, is required to deposit iron inside the particle.

• KSBB Journal
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• 제26권2호
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• pp.119-125
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• 2011

In the synthesis of nanoparticles, much attention has been paid to regulating the particle size. There has been a possible evident that using the central cavity (core) of the protein ferritin has a greatly significant influence on it because the core can generate the nanometer-sized mineral particles of variable metal ions. In this report, recombinant human L-ferritins produced from Saccharomyces cerevisiae were purified and their molecular properties were characterized. The cDNA for human ferritin L chain was also expressed in another host such as Escherichia coli, and the properties of recombinant L-ferritins were compared. From isoelectric focusing experiment, the L-ferritin from the recombinant yeast showed no indication of N-glycosylation. Some post-translational modifications other than N-glycosylation were speculated in the L-ferritins from yeast. A difference was made in the L-ferritins in their iron uptake rates and the initial rate of the L-ferritin from yeast was slightly increased. The reconstitution yield and size distribution of the core minerals were analyzed in the L-ferritins by transmission electron microscopy. The L-ferritin from yeast with higher reconstitution yield (54.5%) showed slightly larger sizes (mean 6.92 nm) with narrower size distribution than the L-ferritin from E. coli. It is, in conclusion, speculated that L-ferritin from yeast is relatively superior to the other, in view of the size of nanoparticle and its relative homogeneity.

• 한국수정란이식학회지
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• 제15권3호
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• pp.247-253
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• 2000

This study was undertaken to optimize enucleation and reconstitution methods for the production of cloned mice by somatic cell nuclear transfer Outbred ICR mouse oocytes at the metapahse- II stage were retrieved from female mice superovulated by PMSG and hCG. In Experiment 1, oocytes were enucleated in medium supplemented with cytochalasin B (CCB) of 3 levels (0, 7.5 or 15 $\mu\textrm{g}$/mL), and higher rate of encleation was obtained at 7.5 and 15 $\mu\textrm{g}$/mL than at $\mu\textrm{g}$/mL. In Experiment 2, oocytes enucleated in 7.5 $\mu\textrm{g}$/mL CCB-containing medium were reconstituted with different types of somatic cell by following methods; 1) cumulus cells by direct cell injection, 2) cumulus cells by electric fusion (1.25 kV/cm, 2 pulses for each 70 $mutextrm{s}$) or 3) STO cells by the electrofusion. Electrofusion of STO cells with enucleated oocytes yielded the greatest (P<0.05) rate of reconstitution without lysis (76%) than any other combinations. Although significant decrease in the rate of somatic cell introduction was found, the electrofusion of cumulus cells yielded better rate of reconstitution than direct injection (0 vs. 18%). In Experiment 3, the duration of electric stimulation for the fusion was changed to either 50 $mutextrm{s}$ or 90 $mutextrm{s}$, but no significant improvement of reconstitution efficacy was obtained. In conclusion, this study showed that ICR mouse oocytes could be used for the production of reconstituted oocytes and a fusion method of 1.25 KV/cm with 2 pulses using 570 cell was the optimal.

• Asian-Australasian Journal of Animal Sciences
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• 제18권4호
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• pp.538-544
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• 2005

The present experiment was conducted to assess the effect of reconstitution (R) on utilization of red sorghum (S) in diets of broiler chickens. Day-old broiler chicks (n=360) were randomly divided into 36 groups of 10 chicks each, and 9 dietary treatments were allotted to 4 groups (replicates) in a completely randomized design. Out of the 9 treatments, one was corn-soy based control (D1). The rest of the treatments were diets consisting of four levels (25, 50, 75 and 100% part of corn) of raw red sorghum (S25-S100) or four levels of reconstituted red sorghum (RS25-RS100). The tannin content reduced from 2.3% to 1.6% after reconstitution of red sorghum. Body weight gain reduced significantly (p<0.01) in diets containing unprocessed red sorghum beyond 33% in diet or reconstituted red sorghum at any level. However, during finishing growth phase the birds receiving either processed or unprocessed sorghum (barring S75) had statistically similar gains in body weight. During over all growth phase (0-6 wk), live weight gains in all the dietary treatments did not differ statistically. Feed intake during 0-6 wk was significantly higher (p<0.05) in diets containing sole red sorghum than corn-soy based control diets Feed conversion ratio during 0-3 wk period in control and unprocessed red-sorghum diets were similar but statistically poorer (p<0.01) FCR emanated from reconstituted groups, while during 3-6 wk of age FCR was poorer (p<0.05) in diets containing 75% red sorghum, either processed or unprocessed. FCR, in overall growth phases, in control diet was statistically similar to the groups fed diets containing up to 33% unprocessed or 16% reconstituted group. The carcass traits and yield of organs did not differ (p>0.05) due to the various levels of red-sorghum. It was concluded that though the tannin content was reduced by 30% by the reconstitution process, but this did not give any additional advantage in broiler performance. More over, red-sorghum can be used effectively up to 33% in diet replacing 50% of corn after proper adjustment of proteins, energy and amino acids.

• 대한의용생체공학회:학술대회논문집
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• 대한의용생체공학회 1996년도 춘계학술대회
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• pp.103-107
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• 1996

In this paper, We propose an algorithm for reconstitution of chromosome images to extract its morphological feature parameters. It is reconstituted from 460 chromosome images using the 32 direction line algorithm. We extract three morphological feature parameters such as centromeric index, relative length ratio, and relative area ratio. The experiment results show that our method is batter than that of other researchers comparing with the error of feature parameters.

• BMB Reports
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• 제35권3호
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• pp.255-261
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• 2002

GTP cyclohydrolase I (E.C. 3.5.4.16) is a homodecameric protein that catalyzes the conversion of GTP to 7,8-dihydroneopterin triphosphate (H2NTP), the initial step in the biosynthesis of pteridines. It was proposed that the enzyme complex could be composed of a dimer of two pentamers, or a pentamer of tightly associated dimers; then the active site of the enzyme was located at the interface of three monomers (Nar et al. 1995a, b). Using mutant enzymes that were made by site-directed mutagenesis, we showed that a decamer of GTP cyclohydrolase I should be composed of a pentamer of five dimers, and that the active site is located between dimers, as analyzed by a series of size exclusion chromatography and the reconstitution experiment. We also show that the residues Lys 136, Arg139, and Glu152 are of particular importance for the oligomerization of the enzyme complex from five dimers to a decamer.

• 헤리티지:역사와 과학
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• 제48권1호
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• pp.148-165
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• 2015

철은 한반도 고대국가의 형성과 발전에 큰 영향을 미친 중요한 요소였다. 이러한 철을 대규모로 생산하기 위해서는 원료인 철광석과 연료인 목탄의 공급이 원활하고 생산된 철기의 유통을 위해 교통로가 발달된 곳이 적합한 입지로 알려져 있는데, 중원지역은 제철에 필요한 3가지 조건을 모두 갖춘 지역으로 제철유적이 다수 확인되었다. 제철유적에서 확인된 철 생산공정을 검토한 후 진천 석장리유적 B-23호 제철로를 복원하여 제철실험을 실시하였다. 실험은 향후 지속적으로 이루어질 제철실험에 반영할 수 있는 다양한 변수를 파악하기 위한 목적으로 실시하였다. 실험결과 첫째, 배소작업은 철광석의 파쇄에 도움을 주는 것을 재확인하였다. 둘째, 송풍관의 용융과 노내 생성물이 송풍을 방해하는 환경조성에 영향을 주는 것을 확인하였다. 셋째, 철은 탄소와 결합됨에 따라 녹는점이 낮아지며, 성질도 변하기 때문에 연소되는 목탄과 충분히 결합될 수 있는 환경조성이 제철조업에 가장 중요한 요소임을 확인할 수 있었다. 고대 제철기술을 복원하기 위해서는 제철유적에서 확인되는 정보의 철저한 분석과 다양한 가능성을 상정하여 실험에 임하는 자세가 필요하다. 이밖에 철의 생산과 유통을 파악하기 위하여 원료의 산지를 밝히기 위한 연구도 적극적으로 수행되어야 할 것이다.

• 헤리티지:역사와 과학
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• 제48권4호
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• pp.138-153
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• 2015

한국 고대 제철기술의 규명을 위한 연구의 일환으로 백제 4세기대 유적인 진천 석장리 B-23호 원형 제철로를 모델로 제철로를 복원하고 전통 방법에 의한 고대 철생산 실험을 실시하였다. 2014년도부터 예비실험을 포함하여 수차례의 실험을 실시하였으며 본 고에서는 1차 및 2차 실험 결과에 대해 검토하고자 한다. 원료와 연료는 각각 철광석(자철석)과 목탄(참나무숯)을 사용하였으며 송풍은 4인용 발풀무를 사용하였다. 제련 생성물은 대부분 노하부에 철괴, 슬래그, 목탄이 뒤섞인 상태로 되어 있었는데 배재부와 송풍관을 기준으로 절단하여 위치별 철괴의 양을 측정한 결과 주로 송풍관측에 상대적으로 많은 양의 철이 형성되었다. 철괴는 생성 위치에 따라 다른 형태의 미세조직과 함탄량을 갖는 것으로 나타났는데 전체적으로는 바닥부에 형성된 철의 함탄량이 상부에 형성된 철에 비해 높은 것으로 나타났다. 동일한 조업에서도 직접 단야 조업에 활용할 수 있는 철소재와 함탄량이 높아 탈탄 처리하거나 주조에 사용할 수 있는 상태의 다양한 철이 생성된 것을 확인하였다. 2차 실험 유출 슬래그를 제외하면 대부분 철함량이 낮은 유리질 슬래그가 형성된 것으로 보아 철과의 분리가 잘 된 것으로 여겨진다. 고고학적 자료를 기본으로 하여 고대 제철로를 복원하고 전통 방법에 의한 조업을 실시함으로써 고대의 철생산 공정에 대한 연구 자료를 확보할 수 있었으며 이를 바탕으로 향후 지속적인 실험을 실시하여 백제 제철기술을 규명할 수 있을 것으로 여겨진다.