• 한국자기공명학회논문지
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• 제4권2호
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• pp.133-139
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• 2000

The strategy to incorporate [$^{15}$ N]-labeled amino acids were discussed. Instead of using specific auxotrophic strains for selective labeling, the prototrophic strain, BL2l(DE3), was used with a plasmid, pLysS, and found to be very effective for several amino acids including alanine, lysine, leucine, and threonine. Isoleucine, valine, glutamine, and tyrosine were also found to be effective despite some diffusion into other amino acids. Interesting result was obtained when [$^{15}$ N]-labeled glycine was tried: only glycines were labeled when amino acid mixture was added in the growth medium, and serines were co-labeled when amino acids were omitted. These results can be used as a guideline when selective labeling strategy is considered, and when the resulting data are interpreted.

• 한국초지학회:학술대회논문집
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• 한국초지조사료학회 1999년도 제24회 정기총회 및 프로그램, 제37회 학술발표회 및 특별강연 초록
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• pp.82-83
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• 1999

탄소 및 질소동화의 상관성을 규명하기 위해 $^{13}$C(pulse chase)와 $^{15}$ N(continuous)을 labeling 한 후 6시간 동안 탄소 및 질소대사물로 동화된 동위원소를 분석하여 엽신, 엽병 및 뿌리조직 사이의 대사적 교감에 있어 탄소 및 질소 동화산물의 역할을 살펴보았다 $^{13}$$CO_2$로 75분간 labeling 한 후(0h), 광합성에 의해 고정된 $^{13}$C는 엽신에서 당의 형태로 주로 동화되었다.(중략)

• 한국자기공명학회논문지
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• 제15권2호
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• pp.115-127
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• 2011

A newly developed cost-effective approach to prepare $^{15}N/^{13}C$-labeled protein for NMR studies is presented. This method has been successfully applied to isotopically labeling of PTK6 SH2 domain and MTH 1880 protein. The production method generates cell density using a growing media containing $^{15}NH_4Cl$, $^{12}C_6$-D-glucose. Following a doubling time period for unlabeled metabolite exhaustion and then addition $^{13}C_6$-D-glucose into a M9 growing media, the cells are induced. Our results demonstrate that in order to get full incorporation of $^{13}C$, the isotopes are not totally required during the initial growth phase before induction. The addition of small amounts of $^{13}C_6$-D-glucose to the induction phase is sufficient to obtain more than 95% incorporation of isotopes into the protein. Our optimized protocol is two-thirds less costly than the classical method using $^{13}C$ isotope during the entire growth phase.

• Journal of Nutrition and Health
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• 제45권2호
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• pp.150-158
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• 2012

This study was conducted to investigate the relationship between knowledge of nutrition labeling and the effect on eating habits with 300 high school boys in Seoul. The subjects were divided into an underweight (UW) group (BMI < $18.5kg/m^2$, n = 42), a normal weight (NW) group ($18.5kg/m^2\;{\leq}\;BMI\;<\;23kg/m^2$, n = 129) and an overweight (OW) group (BMI ${\geq}\;23kg/m^2$, n = 79) based on their body mass index (BMI). The average age of participants was 17.8 years old and their mean height and weight were 174.9 cm and 66.5 kg. The mean BMI of subjects was $21.7kg/m^2$ which fell within the normal range. Seventy six point four percent of subjects perceived nutrition labeling and they acquired the information pertaining to it through TV and internet. The UW group and the OW group obtained it from their parents, relatives and friends, while NW group acquired it from school. There were significant differences among groups in the acquired source of the information on nutrition labeling (p < 0.05). The NW group and the OW group trusted nutrition labeling more than the UW group, but there were no significant differences among them. Forty five point five percent of the UW group and 40.7% the NW group were satisfied with nutrition labeling education, while only 15.8% of the OW group did it. The OW group checked nutrition labeling more than the UW group and the NW group at the point of food purchase. The primary reason for examining nutrition labeling was 'to check nutrient contents' in the UW group and the NW group, while the OW group examined it to improve health including regulation of body weight. There were significant differences among groups with regards to the reason for examining nutrition labeling (p < 0.001). The OW group was aware that nutrition labeling affected their eating ha-bits significantly more than the other groups (p < 0.05). Therefore, application-centered education on nutrition labeling and the strong support of the government is needed in order to improve nutrition labeling use and to apply the information from nutrition labeling into student dietary life.

• 한국자기공명학회논문지
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• 제14권2호
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• pp.117-126
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• 2010

Hsp33 is a molecular chaperone achieving a holdase activity upon response to a dual stress by heat and oxidation. Despite several crystal structures available, the activation process is not clearly understood, because the structure inactive Hsp33 as its reduced, zinc-bound, monomeric form has not been solved yet. Thus, we initiated structural investigation of the reduced Hsp33 monomer by NMR. In this study, to overcome the high molecular weight (33 kDa), the protein was triply isotope-[$^{13}C$, $^{15}N$, $^2H$]-labeled and its inactive, monomeric state was ensured. 2D-[$^1H$, $^{15}N$]-TROSY and a series of triple resonance spectra could be successfully obtained on a high-field (900 MHz) NMR machine with a cryoprobe. However, under all of the different conditions tested, the number of resonances observed was significantly less than that expected from the amino acid sequence. Thus, a possible contribution of dynamic conformational exchange leading to a line broadening is suggested that might be important for activation process of Hsp33.

• 한국자기공명학회논문지
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• 제24권3호
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• pp.77-85
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• 2020

Stable isotope enrichment in proteins is necessary for high-resolution nuclear magnetic resonance (NMR) experiments. Although methods for ¹³C, ¹⁵N and ²H-enrichment in prokaryotic cells are well established, full processing and correct folding of complex protein systems require higher organisms as the expression host. In the present study, we review recent efforts to enrich stable isotopes in mammalian cells for protein NMR studies.

• 대한지역사회영양학회지
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• 제21권6호
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• pp.574-579
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• 2016

Objectives: Vitamin C has various functions such as antioxidative effect and supporting absorption of iron (Fe). Aim of this present study was to provide vitamin C nutrition information and to briefly evaluate absorption interaction of vitamin C and Fe content of vitamin C emphasized products. Methods: Vitamin C emphasized foods including beverages, cereal, snacks, chocolate products, other cocoa products, and sugary products were examined by HPLC. Fe contents in samples after dry-ashing were examined by ICP. Results: Vitamin C content ranges in various products tested were the following: beverages (n=11) $20.15{\pm}0.08{\sim}845.41{\pm}6.07mg$, cereal (n=11) $52.50{\pm}0.23{\sim}262.50{\pm}0.07mg$, snacks (n=1) $50.00{\pm}0.25mg$, chocolate products (n=1) $311.73{\pm}2.44mg$, other cocoa products (n=1) $311.73{\pm}2.44mg$, other sugary products (n=2) $52.50{\pm}0.23{\sim}262.50{\pm}0.07mg$. Vitamin C (n=27) analysis values ranged from 82 to 450% of the labeled value. Vitamin C content in vitamin C emphasized food (n=6) was estimated 7.7 times~56.6 times more than Fe content. Conclusions: Analyzed samples ranged more than 80% of the labeled value in vitamin C emphasized products, which complied with food labeling regulation. But, beverages (n=3), cereal (n=4), chocolate products (n=1) were 2 times more than the labeled value. To provide accurate nutrition information, food manufactures should supervise nutrition labeling and understand the interactions between nutrients. Also, consumer should decide about the adequate amount of nutrient intake by thoroughly checking nutrition labeling.

• 대한핵의학회지
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• 제33권4호
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• pp.430-438
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• 1999

목적: 마이크로웨이브를 이용한 방사성 동위원소의 표지와 Sep-Pak 카트리지를 이용한 정도관리 방법의 개선으로 신속한 제조가 가능하면서도 높은 표지효율을 가진 방사성 의약품을 얻고자 하였다. 대상 및 방법: $C_{18}$ 그리고 alumina N Sep-Pak카트리지를 이용한 정도관리 방법을 $^{99m}Tc$-ECD, $^{99m}Tc$-MIBI, $^{99m}Tc-MAG_3$에 적용하였고 표지효율을 측정하였다. 마이크로웨이브를 사용하여 상기의 키트에 방사성 동위원소를 표지하여 표지효율을 비교하였다. 결과: 마이크로웨이브에 의해 생성된 세 가지방사성 의약품은 3 ml용액에 $^{99m}Tc$-ECD와 $^{99m}Tc$-MIBI는 10초, $^{99m}Tc-MAG_3$는 15초의 짧은 마이크로웨이브를 조사하여 모두 95% 이상의 표지효율을 나타내었다. $^{99m}Tc$-ECD와 $^{99m}Tc$-MIBI는 Sep-Pak alumina N 카트리지를 사용하여 짧은 시간 내에서도 정확한 정도관리 결과를 얻을 수 있었다. 방사성 의약품의 제조시간은 정도관리를 포함하여 모두 6분 이하를 나타내었다. 결론: Sep-Pak 카트리지를 이용한 정도관리 방법과 마이크로웨이브에 의한 방사성 의약품의 제조 방법은 일상적인 방사성 의약품의 제조에 적용이 가능하였으며, 방사성 의약품의 제조시간을 크게 단축시킬 수 있었다.

• 약학회지
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• 제39권5호
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• pp.516-520
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• 1995

The anti-dansyl antibodies were specifically labeled with stable isotope by growing hybridoma cells in serum-free medium. Assignments of the observed carbonyl carbon resonances have been determined by using $^{13}C-{15}N$ double labeling method in order to assign the Leu resonances. However, when the identical dipeptide appears more than twice in the polypeptide sequences, we applied the proteolytic fragments in the fragment-specific method. Carboxypep-tidase B-treated antibody has also been used to assign the Lys-447 in C terminal amino acid. These unambiguously assigned carbonyl carbon resonances in antibodies are thought to be useful in elucidating not only the structure of antibodies but also the structure-function relationship in the antibody by $^{13}C$ neuclear magnetic resonance spectroscopy.

• 한국초지조사료학회지
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• 제31권3호
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• pp.277-284
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• 2011

가뭄 스트레스 조건에서 마이코라이자의 접종이 질소의 흡수와 동화에 미치는 영향을 구명하기 위해 마이코라이자를 접종한 처리구와 접종하지 않은 처리구에서 수분처리 7일간 총 $^{15}N$, 흡수된 $NO_3^-$로부터 아미노산과 단백질로 합성된 15N 함량을 각각 분석하였다. 정상 관수구에서는 전 조사항목에서 마이코라이자 접종에 대한 유의적인 효과가 나타나지 않았다. 총 $^{15}N$ 함량은 가뭄 스트레스에 의해 마이코라이자 접종구 및 비접종구에서 각각 13.8%, 28.5% 감소하였다. $^{15}N-NO_3^-$ 함량은 비접종구에서 유의적으로 증가하였다. 아미노산으로 합성된 $^{15}N$ 함량은 마이코라이자 비접종구에 비해 접종구의 잎과 뿌리에서 각각 1.26 및 1.33배 증가하였다. 가뭄 스트레스 조건의 잎에서 단백질로 합성된 $^{15}N$ 함량은 접종구보다 비접종구에서 더 높은 비율로 감소하였다. 이러한 결과는 가뭄 스트레스하에서 감소되는 질소흡수, 아미노산 및 단백질 합성을 마이코라이자 접종에 의해 효율적으로 경감시킬 수 있음을 잘 보여준다.